热辐射强度对棉花燃烧特性的影响

Influence of heat radiation intensity on the combustion characteristics of cotton

利用锥形量热仪对两组质量为10、20 g的棉花进行了热辐射点燃实验,热辐射强度分别选取35、30、25、20、15、10、5、4、3、2 kW/m^2,对其热释放速率曲线、总热释放量曲线、燃烧残留物形貌和残余质量进行了对比分析。研究结果表明:棉花明火燃烧时总是同时存在阴燃,明火燃烧的热释放速率峰值高于同条件下阴燃的热释放速率的最大值,随其规模程度的增大而增大。阴燃的热释放速率曲线没有峰值,热释放持续的时间较长。尺寸100 mm×100 mm×24 mm、质量10 g棉花样品的临界点燃热辐射强度为2~3 kW/m^2;尺寸100 mm×100 mm×24 mm、质量20 g棉花样品的临界点燃热辐射强度为4~5 kW/m^2。随着堆积密度、相对湿度增加,临界点燃热辐射强度提高。

Thermal radiation ignition experiment of two groups of cotton with mass of 10 and 20 g were carried out by cone calorimeter. The heat radiation intensity is 35,30,25,20,15,10,5,4,3 and 2 kW/m^2 respectively. The heat release rate curve, total heat release curve, combustion residue morphology and residual mass were compared and analyzed. The results showed that when the cotton is burned, there is always smoldering at the same time. The peak of the heat release rate of open flame combustion is higher than the maximum value of the heat release rate of the smoldering under the same conditions, and increases with the increase of the scale. There is no peak in the smoldering heat release rate curve and the heat release lasts longer. The critical igniting heat radiation intensity of cotton sample with size of 100 mm × 100 mm × 24 mm and mass of 10 g is 2~3 kW/m^2;and that of cotton sample with size of 100 mm × 100 mm × 24 mm and mass of 20 g is 4~5 kW/m^2.As the increase of bulk density and relative humidity of the sample, the critical igniting heat radiation intensity increases.