软质聚氨酯二维阴燃数值模拟研究  

Two-dimensional numerical study on smoldering combustion of flexible polyurethane foam

作　　者：王皓良 李柯苒 杨玖玲 WANG Haoliang;LI Keran;YANG Jiuling(School of Engineering,Sichuan Normal University,Chengdu 610101,China;Sichuan Provincial Key Laboratory of Public Fire Prevention and Control Technology,Chengdu 610101,China)

机构地区：[1]四川师范大学工学院,成都610101 [2]四川省高校重点实验室公共火灾防治技术实验室,成都610101

出　　处：《火灾科学(中英文)》2024年第4期203-213,共11页Fire Safety Science

基　　金：校级人才培养项目(qdf20220307)。

摘　　要：软质聚氨酯泡沫(FPUF)广泛应用于室内家具装饰中,易发生阴燃并可能引发严重的住宅大火。为了探明FPUF阴燃传播与主控机制,基于FPUF材料的化学动力学参数,利用COMSOL Multiphysics 6.0软件中的多孔传热模块、多孔组分质量传输模块及Brinkman方程建立了FPUF竖直方向上的二维阴燃数值模型。该模型主要考虑了多孔介质-聚氨酯的吸热热解和放热氧化以及生成炭氧化(一次炭氧化)和残炭的氧化反应(二次炭氧化),同时包括了流体在多孔介质中的流动以及传热传质过程。主要分析讨论了阴燃过程中各个反应结构、固体、气体组分质量分数以及温度场的分布。模型表明侧边界对流热损失对阴燃传播有抑制作用,边界的对流冷却效应导致阴燃反应集中在区域中心且呈锥形燃烧结构;第一次炭氧化反应放热量是阴燃自维持传播的主要能量供应源;二维阴燃反应区的氧气并没有完全消耗,阴燃主要受到化学动力学控制。该模型揭示的FPUF阴燃机制可为进一步研究阴燃淬火特性(尤其是边界冷却对淬火的影响)及其熄灭极限提供理论支撑,并可为FPUF阴燃火灾的预防和抑制提供指导。Flexible polyurethane foam(FPUF) is prone to smoldering and can cause serious residential fires.In order to explore the smoldering propagation and its main controlling mechanism,a two-dimensional computational model for vertical smoldering is put forward using COMSOL software 6.0 version,using the Porous Heat Transfer Module,the Mass Transport Module,and the Brinkman equations.A four-step reaction scheme describing foam pyrolysis,foam oxidation,char oxidation(primary carbon oxidation),and carbon residue oxidation(secondary char oxidation) is applied in this model.The heat and mass transfer within the porous media are incorporated into this model.Each reaction structure,mass fractions of solid and gas species,and temperature distributions are analyzed and discussed.In addition,the suppression effects of convective heat loss at side boundaries are also elaborated.The model shows that the convective heat loss at side boundaries suppresses the smoldering propagation.The cooling side boundaries cause smoldering to be reacted in the center in a conical structure.The heat release from the first char oxidation reaction is the main heat supply for the self-sustained propagation of smoldering.Oxygen in the two-dimensional smoldering reaction zone is not completely consumed,implying that smoldering is mainly controlled by the chemical kinetics of foam.The smoldering mechanism of FPUF revealed by this model can provide theoretical support for further study of smoldering quenching characteristics(especially the influence of boundary cooling on quenching) and its extinguishing limit,and can guide the prevention and suppression of smoldering fire of FPUF.

关 键 词：软质聚氨酯泡沫 多孔介质 阴燃传播 数值模拟 

分 类 号：X915.5[环境科学与工程—安全科学]