...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Combustion and Flame >An enthalpy-based pyrolysis model for charring and non-charring materials in case of fire
【24h】

An enthalpy-based pyrolysis model for charring and non-charring materials in case of fire

机译：火灾时炭化和非炭化材料的基于焓的热解模型

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

In a simulation of a developing fire, flame spread must be properly accounted for. The pyrolysis model is important in this respect. To that purpose, we develop a simplified enthalpy-based pyrolysis model that is extendable to multi-dimensional solid-phase treatments. This model is to be coupled to gas phase turbulent combustion simulations. The description of the pyrolysis process is simplified in order to acquire short simulation times. In this paper, first, the basic thermodynamic description of pyrolysis phenomena is revisited for charring and non-charring materials, possibly containing moisture. The heat of pyrolysis is defined and its relation to the formation enthalpies of individual constituents is explained. Solving only one equation for enthalpy on a fixed computational mesh, provides a useful description of the transport of heat and the pyrolysis process inside the solid material. Models for e.g. char oxidation or complex transport of the pyrolysis gases or water vapour inside the solid material can be coupled to the present model. Next, numerical issues and implementation are discussed. We consider basic test cases with imposed external heat flux to a solid material that can be dry or contain moisture. We illustrate that continuous pyrolysis gases mass flow rates are obtained when a piecewise linear representation of the temperature field is adopted on the fixed computational mesh. With constant temperature per computational cell, discontinuities, with sudden drops to zero, are encountered, as reported in the literature. We show that the present model formulation is robust with respect to numerical aspects (cell size and time step) and that the model performs well for variable external heat fluxes. For charring and non-charring materials, we validate the model results by means of numerical reference test cases and experimental data. By means of a numerical test case, we show that the model, when coupled to CFD calculations, is able to simulate flame spread.
机译：在模拟火势蔓延时，必须适当考虑火焰蔓延。在这方面，热解模型很重要。为此，我们开发了一个简化的基于焓的热解模型，该模型可扩展到多维固相处理。该模型将与气相湍流燃烧模拟耦合。为了获得较短的模拟时间，简化了热解过程的描述。在本文中，首先，重新讨论了热解现象的基本热力学描述，用于炭化和非炭化材料，其中可能含有水分。定义了热解热，并解释了其与单个成分形成焓的关系。在固定的计算网格上仅求解一个焓方程，就可以很好地描述固体材料内部的热传递和热解过程。例如的模型炭氧化或固体材料内部的热解气体或水蒸气的复杂传输可以耦合到本模型。接下来，讨论数值问题和实现。我们考虑了基本的测试案例，这些案例将外部热流施加到可能干燥或含有水分的固体材料上。我们说明了在固定的计算网格上采用温度场的分段线性表示时，可以获得连续的热解气体质量流量。如文献报道，在每个计算单元温度恒定的情况下，会遇到不连续性，突然下降到零。我们表明，当前的模型公式相对于数值方面（像元大小和时间步长）是鲁棒的，并且该模型对于可变的外部热通量表现良好。对于炭化和非炭化材料，我们通过数字参考测试案例和实验数据来验证模型结果。通过一个数值测试案例，我们证明了该模型与CFD计算结合时能够模拟火焰蔓延。

著录项

  • 来源
    《Combustion and Flame》 |2010年第4期|715-734|共20页
  • 作者

    S.R. Wasan; P. Rauwoens; J. Vierendeels; B. Merci;

  • 作者单位

    Department of Flow, Heat and Combustion Mechanics (IR03), Ghent University-UGent, Sint-Pietersnieuwstraat-41, B-9000 Ghent, Belgium;

    Department of Flow, Heat and Combustion Mechanics (IR03), Ghent University-UGent, Sint-Pietersnieuwstraat-41, B-9000 Ghent, Belgium;

    Department of Flow, Heat and Combustion Mechanics (IR03), Ghent University-UGent, Sint-Pietersnieuwstraat-41, B-9000 Ghent, Belgium;

    Department of Flow, Heat and Combustion Mechanics (IR03), Ghent University-UGent, Sint-Pietersnieuwstraat-41, B-9000 Ghent, Belgium;

  • 收录信息 美国《科学引文索引》(SCI);美国《工程索引》(EI);美国《生物学医学文摘》(MEDLINE);
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

    fire; flame spread; numerical simulations; pyrolysis model; charring; non-charring;

    机译：火;火焰蔓延;数值模拟;热解模型烧焦不充电;

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号