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通过建立现代建筑夹层模型,研究铺设大量电缆可能引发的火灾效应,探索夹层内电缆火灾特性,找到电缆在夹层内的合理铺设方式,为制定科学合理的防火对策提供依据。本文主要讨论了不同因素对火焰蔓延速度,烟气温度和有害物质生成浓度的影响,并评价了有害物质的毒害作用。结果表明,夹层内铺设电缆的数量、铺设角度和距离夹层底层远近对电缆的燃烧特性有明显影响。1根电缆时火焰蔓延速度为3.17×10~(-3)m/s,两根时为3.96×10~(-3)m/s;1根电缆情况下,铺设角度由45°到垂直状态时,蔓延速度由4.01×10~(-3)m/s增加到26.09×10~(-3)m/s,产生烟气温度和烟气中有害成分浓度也随之增高;垂直条件下,烟气质量浓度在230 s时达到最高值12.50 g/m~3,产物CO的质量浓度远远超出OSHA标准(1.88 g/m~3)。因此,电缆在夹层内垂直燃烧时发生火灾的危险性更大。
By establishing a modern building sandwich model, the fire effects caused by the laying of a large number of cables can be explored, the fire characteristics of the cables in the interlayer can be explored, the reasonable laying way of the cables in the interlayer can be found, and the basis for developing scientific and reasonable fire prevention measures can be provided. This paper mainly discusses the influence of different factors on flame spread speed, flue gas temperature and concentration of harmful substances, and evaluates the poisoning effect of harmful substances. The results show that the number of laying cables in the interlayer, laying angle and the distance from the bottom of the interlayer have a significant impact on the combustion characteristics of the cable. When a cable is used, the flame spread speed is 3.17 × 10 -3 m / s and the two are 3.96 × 10 -3 m / s. In the case of one cable, the laying angle is from 45 ° to the vertical , The spreading speed increased from 4.01 × 10 -3 m / s to 26.09 × 10 -3 m / s, the flue gas temperature and the concentration of harmful components in the flue gas also increased. Under the vertical condition, The mass concentration of flue gas reaches the highest value of 12.50 g / m ~ 3 at 230 s, and the concentration of CO in the product far exceeds the standard of OSHA (1.88 g / m ~ 3). As a result, there is a greater risk of fire when cables are fired vertically in the mezzanine.