线火源与点火源在巷道火灾中烟流特性对比

Comparative analysis on smoke flow characteristics of line and ignition source in roadway fire

为揭示井下线火源与点火源诱导火灾的不同,达到有针对性的进行矿井火灾防治,依据两种火源类型的燃烧特性,应用火灾动力学模拟软件FDS,建立了符合井下火灾燃烧特点的矿井平巷火灾模型,模拟对比分析了两类火源在相同火灾场景下烟气运动过程、速度分布及温度衰减规律.研究结果表明:在1.2 m/s风速条件下,线火源在顶棚射流过程中烟气的水平运动速度大于点火源,烟流逆流长度较长;巷道中截面火源附近速度最大,可达3.5 m/s,由于节流作用和输送机的遮挡,上风向顶板附近及输送机后部风速减小.顶板最高温度随火源距离的增大出现衰减,且线火源的衰减速度小于点火源,竖向温度由巷道顶板向底板方向递减.因此,线火源的火灾危害性更大,在火灾防治中应该给予更高的关注.

In order to reveal the difference between ignition and line sources induced by fire and to achieve the mine fire prevention and control, this paper established the combustion model of coal mine fire based on the combustion characteristics of two fire sources by using the FDS. The fire smoke flow characteristics of the two type of sources were simulated and comparative analyzed in the same scene. Results show that under the condition of 1.2 m/s wind speed, horizontal velocity line fire is greater than the ignition source in the process of ceiling jet, and the length of the smoke back-flow is longer, and the maximum velocity of the cross section is 3.5 rrds near the fire source. Due to the throttling effect and restriction of the conveyer, wind speed decreases in the upper drift of the roof and the back of the conveyor. The throttle effect of the line source is more obvious. The decay rate of the line source is less than the ignition. The vertical temperature decreases gradually from the direction of the roadway roof to the floor. Therefore, the fire hazard of the line source is larger, and should be given more attention in the fire prevention and control.