半封闭空间阴燃模型及向明火转化的研究

Research on Smoldering Model and Transition from the Smoldering to Flaming Combustion in Semi-Closed Space

为了了解在半封闭空间中阴燃的机制,对水平放置在实验体中的聚氨酯泡沫进行了阴燃实验研究.结果表明,在半封闭空间中,阴燃反应区域温度低且变化幅度小.根据在此条件下阴燃的特点,建立了阴燃区域的模型.分析表明,该模型在未反应区(未燃材料区)中符合得很好,在碳层区中除了接近材料末端处的温度外,其余各处误差不大.从阴燃转明火的实验研究中发现,在半封闭空间中的阴燃很难形成明火,能否向明火转化主要由泡沫中氧气含量控制.

In order to understand the mechanism of smoldering of polyurethane foam in a semi-closed space, experiments are con- ducted with horizontally-oriented polyurethane foam. The result indicates that under the semi-closed condition the temperature is low and ranges by a small margin in the reaction zone. Based on the characteristics of smoldering in the semi-closed space, a model is constructed to describe different zones. The analysis shows that the experimental result is well consistent with the model in original material zone; and that the error is small between the model and the experiments in carbonaceous zone except near the bottom of the foam.Furthermore, an experimental study is conducted on the transition from smoldering to flaming combustion of polyurethane foam in the semi-closed space. The result shows that in this condition, the transition from smoldering to flaming is difficult because it depends on oxidation concentration in the foam.