基于量化模型的含磷盐细水雾-惰性气体熄灭油池火试验研究

Experimental study on the extinguishing of oil pooltype flames by fine water mist-inert gas containing phosphorus salts based on a quantitative model

选取一种天然绿色磷盐添加剂植酸钠作为细水雾添加剂,并与常用灭火磷盐添加剂次磷酸铵进行对比,同时选取两种惰性气体(N_(2)、CO_(2)),通过自主设计搭建研究气液灭火介质的杯式燃烧器试验装置,分别对含添加剂细水雾以及含添加剂细水雾-惰性气体复合灭火剂进行熄灭乙醇火和正庚烷火试验,并通过自主建立灭火剂物理化学抑制作用量化模型,对灭火剂灭火作用进行评估,分析灭火作用机制。结果表明,加入两种磷盐添加剂均可提升细水雾的灭火效果,1%、3%质量分数时植酸钠提升较次磷酸铵更加明显,且植酸钠细水雾存在最佳灭火浓度:植酸钠细水雾在3%质量分数时灭火效率达到最佳,5%质量分数时不如纯水细水雾;次磷酸铵细水雾则随着质量分数的增高最小灭火摩尔分数持续降低。对于气液复合灭火剂,惰性气体对细水雾灭火效率有不同程度的提升,且CO_(2)相较于N_(2)作用更明显。同时,对于同类型灭火剂,量化模型评估灭火剂的化学系数与灭火效率具有很好的对应性。

A natural green phosphate salt additive sodium phytate is selected as a fine water mist additive and compared with the commonly used phosphate salt additive ammonium hypophosphite.Two inert gases(N_(2),CO_(2))are selected,and the additive fine water mist and additive fine water mist-inert gas composite extinguishing agent were used to extinguish ethanol and n-heptane fires by independent design and construction of a cup burner experimental device for studying gas-liquid fire extinguishing media.The experiments were carried out on ethanol fire and n-heptane fire,and the mechanism of fire extinguishing effect was evaluated by establishing a quantitative model of physicochemical inhibition of fire extinguishing agents.The results show that the addition of two phosphorus salt additives can improve the fire extinguishing effect of fine water mist,1%and 3%mass fraction of sodium phytate improve the effect more obvious than ammonium hypophosphate,and sodium phytate fine water mist is the best fire extinguishing concentration.Sodium phytate fine water mist at 3%mass fraction has the best fire extinguishing efficiency,5%mass fraction of that is not as good as pure water fine water mist.The minimum fire extinguishing fraction continues to decrease with the increase in mass fraction of ammonium hypophosphate fine water mist.For the gas-liquid composite extinguishing agent,inert gas on the fine water mist extinguishing efficiency has different degrees of improvement,and CO_(2)is more effective compared to N_(2).Meanwhile,for the same type of extinguishing agent,evaluated by quantitative model,the chemical coefficient of the extinguishing agent and the extinguishing efficiency are with good correspondence.