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[1] Jia Baoshan, Xie Maozhao,. Numerical study of forward smoldering combustionof polyurethane foam [J]. Journal of Southeast University (English Edition), 2007, 23 (2): 278-284. [doi:10.3969/j.issn.1003-7985.2007.02.025]
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Numerical study of forward smoldering combustionof polyurethane foam()
聚氨酯泡沫燃料正向阴燃传播特性的数值模拟
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Journal of Southeast University (English Edition)[ISSN:1003-7985/CN:32-1325/N]

Volumn:
23
Issue:
2007 2
Page:
278-284
Research Field:
Chemistry and Chemical Engineering
Publishing date:
2007-06-30

Info

Title:
Numerical study of forward smoldering combustionof polyurethane foam
聚氨酯泡沫燃料正向阴燃传播特性的数值模拟
Author(s):
Jia Baoshan1;  2;  Xie Maozhao1
1 School of Energy and Power Engineering, Dalian University of Technology, Dalian 116024, China
2 School of Safety Science and Engineering, Liaoning Technical University, Fuxin 123000, China
贾宝山1;  2;  解茂昭1
1大连理工大学能源与动力学院, 大连 116024; 2辽宁工程技术大学安全科学与工程学院, 阜新 123000
Keywords:
polyurethane foam;  forward smoldering;  porous medium;  smoldering velocity;  numerical study
聚氨酯泡沫;  正向阴燃;  多孔介质;  阴燃速度;  数值模拟
PACS:
O642.1
DOI:
10.3969/j.issn.1003-7985.2007.02.025
Abstract:
A two-dimensional and two-phase numerical model is presented for the smolder propagation in a horizontal polyurethane foam.The chemical processes considered include endothermic pyrolysis and exothermic oxidation degradation of polyurethane foam and exothermic oxidation of char.The governing equations are discretized in space using the finite element method and solved by the software package FEMLAB.Predicted profiles of solid temperature as well as evolutions of solid compositions(including foam, char and ash)are presented at an airflow velocity of 0.28 cm/s.The computed average smoldering velocity is 0.021 4 cm/s, and the average maximum temperature is 644.67 K.Based on the evolutions of solid compositions, the packed bed can be obviously divided into four zones:unreacted zone, fuel pyrolysis and oxidation zone, char oxidation zone and fuel burned-out zone.Simultaneously, the effects of inlet air velocity and fuel properties(including thermal conductivity, specific heat, density and pore diameter)are studied on the smoldering propagation.The results show that the smoldering velocity and temperature have a roughly linear increase with increasing inlet air velocity;the fuel density is the most important factor in determining smoldering propagation;radiation has a non-negligible role on the smoldering velocity for larger pore diameters of porous material.The computational results are compared with the experimental data and a general agreement is reached.
以聚氨酯泡沫为试样, 建立了多孔介质水平燃料床阴燃的二维两相流数学模型.模型包括燃料吸热热解、燃料放热氧化及焦炭的放热氧化3个反应过程.通过有限单元法对聚氨脂泡沫的阴燃控制方程进行离散, 并采用数值分析软件包FEMLAB进行计算求解.数值模拟了来流速度为0.28 cm/s时燃料阴燃的温度分布和固体成分(燃料泡沫、炭粒和灰分)的变化, 其中阴燃传播平均速度为0.0214 cm/s, 阴燃最高温度平均为644.67 K;固体成分的变化曲线明显的将填充床分成4个区域:未燃区、燃料热解氧化区、焦炭氧化区及燃料燃尽区.同时, 模拟研究了来流速度及燃料特性参数(导热率、比热、密度、孔隙直径等)对阴燃传播特性的影响.结果表明:阴燃速度和阴燃温度随着来流速度的增大基本上呈线性增长;燃料密度对阴燃传播影响最大;对于孔径较大的多孔介质燃料, 模型中要考虑辐射的影响.模拟数据与实验数据进行了对比, 结果基本吻合.

References:

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Memo

Memo:
Biographies: Jia Baoshan(1972—), male, graduate, associate professor, jiabaoshan72918@sina.com.cn;Xie Maozhao(corresponding author), male, professor, xmz@dlut.edu.cn.
Last Update: 2007-06-20