西藏高原环境下点式感烟火灾探测器的灵敏度

为研究西藏高原低压低氧环境下烟雾浓度和点式感烟火灾探测器灵敏度的变化,在拉萨和合肥两地标准实验间中,进行国家标准试验火正庚烷火和棉绳阴燃火实验,并对烟雾浓度进行了模拟.研究发现烟雾浓度主要受燃烧质量损失速率的影响,而在拉萨和合肥相同质量损失速率实验产生烟雾浓度近似相等;高原环境对点型散射式光电感烟火灾探测器灵敏度影响较大,对点型离子感烟火灾探测器灵敏度影响不明显.

Sensitivity of point-type smoke fire detectors in plateau environment of Tibet

The variation of smoke concentration and the sensitivity of point-type ionization and photoelectric fire detectors at low atmosphere pressures and low oxygen concentrations in the plateau environment of Tibet was researched.Two national standard test fire,n-heptane fire and smouldering cotton fire,were carried out in standard test rooms both in Lhasa and Hefei.And the simulation of the concentration of smoke was conducted.It is founded that the variation of smoke concentration is mainly influenced by the decrease of mass loss rate.But when the mass loss rate in Lhasa is equal to that in Hefei,the results are approximate.It is also found that the sensitivity of scattered photoelectric point-type fire detectors at low atmosphere pressure and low oxygen concentration is much lower than that at normal atmosphere pressure and normal oxygen concentration,but that of the ionization point-type fire detectors is not.