The Characteristic Research Of Fire WhirlFormed By Multiple Pools With Same Diameter In TheVertical Channel WithSide Slit

According to previous statistics,When natural disasters such as fires,lightning or earthquake occur in oil tank storage areas,forests and other areas,it is likely to cause multiple fires to form mass fires,and easily induce the occurrence of special fire phenomena such as flame fusion or fire whirlwind.Fire whirlwind is a special kind of fire behavior in fire,it has high flame height,fast combustion rate and wide fluctuation range.With its destructive force,bringing about countless losses in both lives and property.In the past,research on the single-pool fire whirlwind has achieved fruitful results,while the literature on Multiple pool fire is relatively few.Further research on the multi-pool fire fusion fire whirlwind has certain practical significance and guiding significance for the prevention and control of mass fires.This paper mainly adopts experimental methods to explore the influence of different factors on the formation and characteristics of Multiple pool fire whirlwind in the vertical channel of small-size side slits.Supplemented by fire dynamics simulation software FDS4.0,which was used to simulate theMultiple pool fire combustion experiments.The main content includes the following three aspects:(1)Changing the center distance of the oil pool.Through the experimental results,it is found that the average flame height of the Multiple pool fire,the temperature peak on the central axis and the average mass loss rate exhibits increase first and then decrease with the increase of the dimensionless center spacing.Thena critical dimensionless center spacing S' = 2 is obtained;by further supplementing the simulation,a more accurate critical center spacing S' = 2.1 is obtained.(2)Changing the width of the channel side slit and controlling the natural convection intensity.Through the experimental results,it is found that the difficulty level of the formation of Multiple pool firewhirlwind exhibitsdecrease first and then increase with the increase of the width of the side slit;With the increase of the width of the dimensionless side slit,the average flame height,the central axis temperature peak and the average mass loss rate of the multi-cell fire increase first and then decrease,and a critical dimensionless side slit width d'=0.156 is obtained.By further supplementedwith simulation,a more precise critical side slit width d' = 0.141 is obtained.(3)Changing the number of oil pools to carry out Multiple pool fire combustion.It is found that the average flame height,the central axis temperature peak and the average mass loss rate increase with the number of oil pools increases.And the empirical relationship model between the Multiple pool fire combustion fusion flame height and the heat release rate in the vertical channel is obtained.