基于锥形量热仪的计算机显示器燃烧特性分析

利用锥形量热仪对计算机显示器材料进行小尺寸燃烧性能试验研究,通过改变锥形量热仪的热辐射强度模拟中、小规模火灾。分析火灾中显示器样品的热释放速率(HRR)、质量损失速率、CO产生率和比消光系数。试验发现当热辐射强度为35 kW/m2时,计算机显示器的热释放速率比其在热辐射强度为75 kW/m2时多一个加速增长阶段,主要原因是在此热辐射强度下,材料热解速度缓慢,表面炭层厚度逐渐增厚,热量积聚后,材料热解速度增大,热释放速率加速达到第二个峰值;显示器材料在2种热辐射强度下的质量损失速率分3个阶段,炭层的包覆作用对其质量燃烧速率影响较小;显示器材料在燃烧过程中CO产生率、比消光系数和质量燃烧速率成线性递增关系。试验结果可反映显示器在真实火灾中的燃烧特性。

Analysis of Combustion Characteristics of Computer Monitor in Conic Calorimeter Test

Small-scale burning experimental study on computer monitor was done based on a cone calorimeter.Small and middle scale fires were simulated through changing the heat radiation power of cone calorimeter.The heat release rates,mass loss rates,production rates of CO and extinction coefficient were measured in the experiment.The heat release rate(HRR) has an additional increase phase when the heat radiation is 35 kW/m 2.The main reason is that the slow speed of pyrolysis causes the increasing of the thickness of carbon layer on surface,and then with the heat accumulating,the pyrolysis increases and the HRR reaches to the second peak value.The mass loss rate was divided into three phases under 35 kW/m 2 and 70 kW/m 2.The results show that carbon layer on surface has little influence on mass loss rate.There exists a linear increasing relationship among the production rate of CO,extinction coefficient and mass loss rate.The experiment results can reveal the real combustion characteristics of computer monitor on fire.