辐射热流作用下皮棉燃烧特性

Burning behaviors of ginned cotton under external heat flux

为提升皮棉仓库安全管理水平,预防火灾事故,采用燃烧热释放速率试验方法,借助锥形量热仪系统地研究了不同密度打包皮棉在不同辐射热流强度下的燃烧行为及差异,并借助热失重分析仪分析了皮棉在不同温度下的等温热失重情况。结果表明:皮棉的燃烧状态与密度、辐照强度和是否外加点火源均存在很大的关系;辐射强度大于15 k W/m2,相对致密的皮棉在外加点火源后产生明火,不外加点火源时为阴燃;外加点火源时,相对松散皮棉在10~35 k W/m2辐射强度区间内逐步发生燃烧状态转变;辐射强度达到35 k W/m2时,不同密度的皮棉试样在外加点火源时引燃时间均为7 s左右,极易燃烧;皮棉在长时间经受超过15 k W/m2的辐射强度时,可以完全分解。

In order to improve the safety management level of ginned cotton warehouses and prevent fire accidents,using the combustion heat release rate test method,the combustion behavior and difference of packaged ginned cotton with different densities under different radiant heat fluxes were studied systematically by cone calorimeter,and the isothermal thermo weightlessness of ginned cotton at different temperatures was analyzed by means of thermo gravimetric analyzer.The results show that the combustion state of ginned cotton has a great relationship with density,heat flux and fire source.When the fire flux is greater than 15 kW/m 2,the relatively dense ginned cotton generates an open flame after it is ignited by the fire source and is in smoldering when it is not ignited.When ignition occurs,with the heat flux improved gradually from 10 kW/m 2 to 35 kW/m 2,the combustion state of relatively loose ginned cotton would change accordingly.When the radiation intensity reaches 35 kW/m 2,the ignition time of the ginned cotton samples with different densities is about 7 s,which is highly inflammable.The ginned cotton can be completely decomposed when being exposed to heat flux above 15 kW/m 2 over an extended period of time.