Research On Huge Warehouse Stacking Characteristics’ Influence On The Water Cannon’s Vaporific Spray Fire Control Performance

With the establishment and rapid development of market economy in our country, warehouse is playing an growing important role in social logistics. Logistics warehouse, with long span and colossal space, receives wide welcome in various industries. Large space warehouse features huge floor space, high headroom, massive stacking and indeterminate cargo species, comparing with traditional warehouse. Therefore, once fire broke out, great casualties and property loss may occur, because of the difficulty in early fire detection and fire distinguishing, the long duration of the fire and the easy spread between stacking in large space warehouse fire. For instance, in October11th,2013, the fire broke out in large space warehouse of Zhejiang Fabei industrial co., Ltd, resulting hundreds of millions loss; multiple death also happened in Changzhou Beichen Warehouse co., Ltd, Changzhou, Hebei, in April18th,2011. Consequently, the fire safety of the large space warehouse is a crucial issue.Large space warehouse mainly includes the large space stacking warehouse and the high rack warehouse. Traditional automatic sprinkler system fails to control or distinguish the fire in large space stacking warehouse. Automatic fire protection water cannon whose installation height is not constrained by the height of large space, featuring the automatic fire detection and collimation, extinguishing fire at exact point, shorter detection time, and high extinguishing efficiency, has been widely employed in large space stacking warehouse. However, the shield effect of the high stacking would reduce the extinguishing efficiency of the water cannon. Meanwhile, the columnar jet also influence the effectiveness of the water cannon. However, adopting vaporific spray, with large cover area and small impact, in water cannon system, the extinguish efficiency would be improved. In the meantime, enlarging the distance between the stacking would reduce the shield effect of the stacking. Nevertheless, few researches have focused on the influence of the stacking storage on the vaporific spray water cannon efficiency. By conducting pre-spraying, water distribution and fire extinguishing experiments, the stacking storage’s effect on the spraying intensity distribution and fire control capacity of vaporific spray were investigated. Referring to different spraying intensity under the conditions of different stacking height, the minimum safety distance between stacking and the effective protection area were conducted. Full scale experiments also been conducted to inspect the extinguishing effectiveness of vaporific spray water cannon. The results illustrate that the warehouse fire could be effectively controlled or extinguished within the effective range (5m-15m) of the water cannon, fixing at the altitude of8meters and with a atomization angle of90degrees, employed in this paper. The effective area and the spray intensity both decrease as the distance increases. Under the circumstances of warehouses feature hazard level Ⅰ and Ⅱ, the effective area were27.5m2and25.5m2respectively at the range of5meters, with the stacking height from3.0meters to3.5meters. There is a maximum separation distance between the stacks while the stacking height is fixed. The fire could not be put out when the separation distance is smaller than this minimum value.This paper would be reference for the parameter optimization design in automatic fire protection water cannon system and improvement in safety distance design between stacking in large space stacking warehouse.