高原低压环境对细水雾灭火有效性影响研究

Study on the effect of alpine low-pressure environment on the effectiveness of water mist fire extinguishing

为探究高原低压环境对水雾灭火效能的影响,开展了不同环境压力下细水雾雾场特性试验和灭火试验,研究了高海拔低气压环境条件对喷雾特性的影响,揭示了低压环境下细水雾的灭火机制。研究表明:在高原低压环境下,喷头雾锥角不变,增大喷头流量系数K,相同工作压力下低压地区的水雾流量更大。与常压相比,空气密度随着压力的降低而减小,水雾在喷出喷头时与周围空气的相互作用减弱,导致水雾粒径增大。通过灭火试验验证了低压环境下在不改变稀释隔氧作用的前提下,细水雾提高了对高温燃料表面的冷却效果。因此,细水雾在低压环境下的灭火效能更好。

In order to investigate the influence of the high altitude low pressure environment on water mist fire extinguishing effectiveness.Carried out a series of fine water fog field characteristics of different environmental pressure experiments and fire extinguishing experiments,studied high altitude low pressure environmental conditions on the spray characteristics of the relationship,revealed the fire extinguishing mechanism of fine water mist in low-pressure environments.Research has shown that in highaltitude low-pressure environments,with a constant nozzle cone angle,increasing the nozzle flow coefficient K results in a higher water mist flow rate in low-pressure areas under the same working pressure.Compared with normal pressure,air density decreases with decreasing pressure,and the interaction between water mist and surrounding air weakens when sprayed out of the nozzle,resulting in an increase in water mist particle size.Through fire extinguishing experiments,it has been verified that fine water mist improves the cooling effect on high-temperature fuel surfaces in low-pressure environments without changing the dilution and oxygen isolation function.Therefore,fine water mist has better fire extinguishing efficiency in low-pressure environments.