摘要
为了明晰弧形结构聚甲基丙烯酸甲酯(PMMA)的潜在火灾风险性,设计1꞉10的缩尺寸实验平台,测量和分析火蔓延速度、质量损失速率和火焰长度等关键参数的演化规律,研究弧度对弧形结构PMMA火蔓延行为的影响规律和控制机理。研究结果表明:弧形结构PMMA火蔓延过程呈现2个阶段的演变行为,包括减速阶段(顺流蔓延过程)和稳定阶段(逆流蔓延过程),提出减速阶段时变火蔓延速度和质量损失速率的经验关系。基于预热区均匀热流的假设和能量守恒关系,建立稳定阶段质量损失速率和火蔓延速度数学预测模型。此外,稳定阶段平均质量损失速率随弧度增加先减小(30°≤θ<90°)后增大(90°≤θ≤180°),平均火焰长度则先减小后保持不变,而且通过传热分析,揭示了随弧度增加火蔓延过程由气相传热主导向固相导热主导的控制机理。
To clarify the potential fire risk of polymethylmethacrylate(PMMA)with arc structure,small-scale experiments of 1꞉10 were designed,and important parameters,including flame spread rate,mass loss rate,and flame length,were measured and analyzed.Moreover,the influence of the radius of curvature on flame spread behaviors over arc structure PMMA was studied.The results show that the flame spread process of arc structure PMMA can be classified into two stages,namely decelerated stage(upward flame spread)and steady stage(downward flame spread).In the decelerated stage,empirical correlations are proposed to predict the time-varying flame spread rate and mass loss rate.Also,based on the assumption of the uniformly distributed heat flux in the preheating zone and the law of energy conservation,the predictions of mass loss rate and flame spread rate are proposed in the steady stage.In addition,the average mass loss rate in the steady stage decreases first(30°≤θ<90°)and then increases(90°≤θ≤180°)along with a bigger radian.However,flame length shows a decrease first and then stable tendency with the increase of the radian.Through heat transfer analysis,it is found that the controlling mechanism transfers from gas-phase heat transfer to solid-phase heat conduction with the increase of the radian.
作者
卜蓉伟
陈飞
张笑男
周洋
BU Rongwei;CHEN Fei;ZHANG Xiaonan;ZHOU Yang(School of Civil Engineering,Central South University,Changsha 410075,China;Hunan Vocational Institute of Safety Technology,Changsha 410151,China)
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2022年第10期4115-4122,共8页
Journal of Central South University:Science and Technology
基金
湖南省自然科学基金资助项目(2021JJ30860)
中南大学中央高校基本科研业务专项资金资助项目(2021zzts0238)。
