摘要
为了研究灭火过程中超细微粒灭火剂与火焰的相互作用,该文数值模拟了火场中超细微粒灭火剂在不同驱动压力下喷射后的运动特性。采用驱动速率模型、离散相模型和火源模型对灭火剂颗粒的释放、流动以及与火源作用的过程进行数值模拟。模拟结果表明:内壁收缩的喷嘴能够加强微粒穿透火羽流的能力,其穿透能力随着驱动压力的增大而增强。当与灭火剂微粒作用时,火焰高度减小,宽度增大。驱动压力越大,微粒到达火源表面所需要的时间越少;当达到全淹没状态时,在1.2 MPa的驱动压力下,火源处微粒浓度较高。在1.0 MPa的驱动压力下,火源处微粒浓度变化较小;较高驱动压力可以加快微粒在灭火室中全淹没状态形成的时间;当驱动压力较小时,更容易出现涡流,导致微粒快速充满整个灭火室,但是微粒浓度分布不均。
In order to research the interaction between superfine powder extinguishing agents（ SPEA） and fire plume, the injection and movement characteristics of SPEA particles are numerically simulated in fire at different driving pressures. The interaction process of injection velocity model, discrete phase model,and fire model on the particles release,flow,and fire is numerically simulated. The simulation results indicate that the converging nozzle can enhance the capacity of extinguishing agent particles to penetrate fire plume, and its penetration capacity is directly proportional to the driving pressure value. When the fire interacts with the particles,the height decreases and the width increases. The larger the driving pressure becomes,the shorter the time for particles to enter into fire＆amp;nbsp;source area becomes. Particle concentration value in fire source area is relatively higher at 1. 2 MPa and smaller at 1. 0 MPa. Larger driving pressure can accelerate the motion time of particles to fill the extinguishing room. Eddies, which appear more easily at lower driving pressure, can also drive particles to fill the extinguishing room quickly,but with uneven distribution.
出处
《南京理工大学学报》
EI
CAS
CSCD
北大核心
2014年第1期154-160,共7页
Journal of Nanjing University of Science and Technology
关键词
超细微粒灭火剂
运动特性
火羽流
superfine powder extinguishing agents
movement characteristics
fire plume
