【摘要】 在符合ISO 9705标准的试验台上,选取4种不同厚度的杉木板开展全尺寸试验,用红外热像仪测量热解前锋蔓延速率,即壁面垂直向上火蔓延速率。结果表明,垂直向上火蔓延可划分为3个阶段,即点燃阶段、过渡阶段和发展阶段。点燃阶段发生在点火后约40～120s,过渡阶段发生在点火后约200～300 s,发展阶段的开始时间与木板厚度明显成线性关系,木板厚度越大,发展阶段开始得越晚。点燃阶段火蔓延速率加速增长,且与材料厚度不呈线性关系;过渡阶段火蔓延速率负增长;发展阶段火蔓延速率加速增长,且与材料厚度线性相关。更多还原

【Abstract】 To study the pyrolysis front-spreading speed, the paper has done a full scale experiment in accordance with the ISO 9705 standard by choosing four kinds of China Fir boards of different thicknesses, measured by the infrared thermal imager in the method of isotherm and calibration line. The research results we have gained prove that the whole process of the vertical flame spreading should be divided into three stages: ignition stage, transition stage and propagating stage. By ignition stage we mean the short period from 40 seconds to 120 seconds after ignition; the transition stage is referred to the period from 200 seconds to 300 seconds after ignition; Then the beginning of the propagating stage keeps a linear relationship with the thickness of the board. During the ignition stage, the flame propagating velocity accelerates with no linear relationship with the material thickness; However, during the transition stage, the flame spreading velocity has a negative increase whereas in the propagating stage, the flame spreading velocity accelerates and keeps a linear relationship with the material thickness.更多还原