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细水雾与酥油池火相互作用的初始阶段,或细水雾不能有效抑制酥油池火时,往往会发生火焰燃烧被强化的现象。为了深入认识这一现象的发生机理,通过模拟试验研究水滴撞击到不同温度酥油表面的动力学过程。试验中水滴的初始直径为(2.61±0.1)mm,韦伯数为77.9;酥油温度变化范围为200～300℃。整个碰撞过程采用Photron Fastcam高速摄影仪进行拍摄记录。结果表明:水滴撞击到高温酥油油池时,水滴会迅速蒸发并在酥油中生成气泡,气泡上升到酥油-空气交界面时破裂,或者在油池内部发生蒸汽爆炸导致酥油液滴或酥油液柱飞溅;当酥油温度达到300℃时,水滴进入酥油后114 ms左右即发生剧烈的蒸汽爆炸,大量高温酥油被溅起,这应该是导致细水雾熄灭酥油池火时发生火焰燃烧被强化的主要原因之一。
The initial stage of the interaction between the water mist and the butter pool fire, or the water mist can not effectively inhibit the butter fire pool, the phenomenon of flame combustion is often intensified. In order to deeply understand the mechanism of this phenomenon, the kinetic process of droplet impinging on the surface of ghee at different temperatures was studied through simulation experiments. The initial diameter of the droplet was (2.61 ± 0.1) mm and the Weber number was 77.9. The temperature of the shortening varied from 200 ℃ to 300 ℃. Photron Fastcam high-speed camera recording the entire collision process. The results show that when the droplet impinges on the high-temperature butter sump, the water droplets rapidly evaporate and generate bubbles in the butter, which break when the bubble rises to the ghee-air interface or steam explosion inside the sump causes the butter or ghee Splashing; When the butter temperature reaches 300 ℃, the water droplets into butter shortly after 114 ms that violent steam explosion occurred, a large number of high-temperature butter was splashed, which should be the result of the water mist extinguishing butter fire flame flame was enhanced when the main one of the reasons.