非连续介质热解挥发分对其着火的影响
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摘要
建立非连续介质热解挥发分的运动填充模型,推导出热解挥发份的空间浓度分布函数表达式,得出非连续介质热解质量通量对其着火影响的函数关系,并用小规模燃烧实验进行验证。结果表明,室内火灾时非连续介质表面上方一定高度的某点处热解挥发分的浓度与其在该点的质量通量成正比,与其在该点的流动速度成反比;室内火灾时非连续介质要着火燃烧,其热解质量通量必须达到临界值,该临界值大小与烟气层达到稳定时的高度有关。
By building the filling model of pyrolytic volatiles of discrete objects,the functional expression of space concentration distribution of pyrolytic volatiles was deduced,and then the mathematical relationship between the pyrolytic mass flux of discrete objects and their ignition was gained,and small scale fire experiments were done to verify them.The results showed that,in enclosure fires,the pyrolytic volatiles concentration at some height above the discrete object is proportional to the mass flux,and inversely proportional to the flow rate;in enclosure fires if the discrete objects catch fire then their pyrolytic mass flux must reach a certain threshold which is related to the stable height of smoke layer.
By building the filling model of pyrolytic volatiles of discrete objects,the functional expression of space concentration distribution of pyrolytic volatiles was deduced,and then the mathematical relationship between the pyrolytic mass flux of discrete objects and their ignition was gained,and small scale fire experiments were done to verify them.The results showed that,in enclosure fires,the pyrolytic volatiles concentration at some height above the discrete object is proportional to the mass flux,and inversely proportional to the flow rate;in enclosure fires if the discrete objects catch fire then their pyrolytic mass flux must reach a certain threshold which is related to the stable height of smoke layer.
引文
[1]牛贵来,夏长天.室内火灾中非连续介质着火危险性影响因素[J].消防科学与技术,2011,30(7):605-607.
[2]杜文锋.消防燃烧学[M].北京:中国人民公安大学出版社,1997.
[3]牛少伟.关于轰燃定义、机理和判据的讨论与分析[J].沈阳航空航天大学学报,2012,29(2):81-85.
[4]牛贵来,刘雪源,赵洪光.高温烟气层对室内非连续介质着火的影响[J].河南理工大学学报(自然科学版),2011,30(4):396-400.
[5]薛伟,林繁云,耿志伟.原木燃烧羽流的数值模拟研究[J].消防科学与技术,2015,34(12):1567-1570.
[6]牛贵来.木材在锥形量热仪上的点燃实验研究[J].沈阳航空航天大学学报,2011,28(3):74-77.
[7]牛贵来,唐永国,夏长天.室内火灾烟气层高度的理论与模拟研究[J].科学技术与工程,2011,11(22):5355-5360.
[8]栗朝阳.通风因子对有机玻璃燃烧速率的影响[J].消防科学与技术,2012,31(6):566-568.
[2]杜文锋.消防燃烧学[M].北京:中国人民公安大学出版社,1997.
[3]牛少伟.关于轰燃定义、机理和判据的讨论与分析[J].沈阳航空航天大学学报,2012,29(2):81-85.
[4]牛贵来,刘雪源,赵洪光.高温烟气层对室内非连续介质着火的影响[J].河南理工大学学报(自然科学版),2011,30(4):396-400.
[5]薛伟,林繁云,耿志伟.原木燃烧羽流的数值模拟研究[J].消防科学与技术,2015,34(12):1567-1570.
[6]牛贵来.木材在锥形量热仪上的点燃实验研究[J].沈阳航空航天大学学报,2011,28(3):74-77.
[7]牛贵来,唐永国,夏长天.室内火灾烟气层高度的理论与模拟研究[J].科学技术与工程,2011,11(22):5355-5360.
[8]栗朝阳.通风因子对有机玻璃燃烧速率的影响[J].消防科学与技术,2012,31(6):566-568.