Influence of low air pressure on combustion characteristics and flame pulsation frequency of pool fires
Influence of low air pressure on combustion characteristics and flame pulsation frequency of pool fires
复制标题
低气压对池火燃烧特性及火焰脉动频率的影响
DOI：
10.1016/j.fuel.2011.03.035
复制
发表时间：
2011-08-01
期刊：
影响因子：
7.4
通讯作者：
Zhang, Yong-ming
中科院分区：
文献类型：
--
作者：
Fang, Jun;Tu, Ran;Zhang, Yong-ming
为了研究低气压对池火燃烧特性和火焰喷燃频率的影响，在拉萨（海拔3650 m，气压65 kPa）和合肥（海拔24 m，气压100.8 kPa）两个实验室，用15个不同尺寸的方形燃烧器对乙醇和正庚烷池火进行了实验。两地相同规模池火实验结果比较表明，首先，拉萨火焰中心线温度最大上升幅度普遍大于合肥。燃烧速率指数n（m/n）与空气压力的关系随燃烧器当量直径D的变化而变化，n < 0（D < 7 cm），（0-1）（7 cm < D < 10 cm），（1-1.45）（10 cm < D < 19 cm）和1（D > 19 cm）。第三，低气压下池火火焰的辐射份额较小。最后，低气压下池火火焰的膨化频率较高。与合肥相比，在拉萨，对于相同尺寸的燃烧器，观察到更高的最高温度和更少的火焰辐射。这表明，在低气压下，池火更浮力，导致更强的周期振荡和更高的火焰膨化频率。(C)2011爱思唯尔有限公司版权所有。
To investigate the effect of low air pressure on the combustion characteristics and puffing flame frequency of pool fires, ethanol and n-heptane pool fires were performed using 15 square burners of various size in both Lhasa (altitude: 3650 m; air pressure: 65 kPa) and Hefei (altitude: 24 m, air pressure: 100.8 kPa) fire laboratories. Comparison of the experimental results for pool fires of the same size in the two places shows that, firstly, the maximum rise in the centerline temperature in flames in Lhasa is generally larger than that in Hefei. Secondly, the dependence of the burning rate exponent n ((m) over dot '' proportional to p(n)) on the air pressure varies with the equivalent diameter D of the burner, with n < 0 (D < 7 cm), (0-1) (7 cm < D < 10 cm), (1-1.45) (10 cm < D < 19 cm) and 1 (D > 19 cm). Thirdly, radiation fraction of the pool fire flames is smaller at low air pressure. Finally, the puffing frequency of the pool fire flames is higher at low air pressure. Compared with Hefei, in Lhasa, for the same size burner, a higher maximum temperature together with less radiation from the flame is observed. This shows that in low air pressure, the pool fire is more buoyant, which leads to stronger periodic oscillation and a higher flame puffing frequency. (C) 2011 Elsevier Ltd. All rights reserved.