Studies On Temperature And Smoke Evolutions Of Corridor Fires Under The Effects Of Sprinkler

The interior of the buildings has the characteristics of dense personnel and sufficient combustibles.Therefore,the fire hazards and the accident risks are high.When a building fire occurs,the smoke will enter the corridor through doors and windows,thus expanding the spread of the fire.The sprinkler can change the temperature characteristics of fire and the law of smoke evolution.It is of great significance to study the temperature and smoke evolutions of corridor fires under the effects of sprinkler for guiding fire fighting and evacuation when a fire occurs.This paper built a 1:6 small size building corridor fire experiment platform,and study the effects of fire source power on the temperature distribution and the smoke flow of the corridor fires under experimental conditions without sprinkler.The experimental results demonstrate that the higher the fire source power,the larger the temperature difference between the hot smoke layer and the cold air layer,but the influence of fire source power on the temperature at the bottom of the corridor is less.Increasing fire source power can also lead to the acceleration of smoke flow speed and increased smoke.Using the method of small size experiment combined with the method of small size FDS numerical simulation,study the effects of sprinkler parameters on the temperature evolution characteristics and the smoke spreading characteristics of the corridor fires.The experimental results demonstrate that:With the increase of the sprinkler diameter,the smoke temperature and smoke flow speed decrease,and the trend of sedimentation of the smoke layer increases;With the increase of the sprinkler working pressure,the temperature of the corridor decreases obviously,and the smoke flow speed also decreases,thus affecting smoke extraction efficiency;When the fire source and the sprinklers are not on the same central axis,the smoke temperature and the smoke flow speed are always in the rising phase,and the height of the smoke layer does not decrease significantly;When the fire source power is small,with the increase of the fire source power,the smoke flow speed does not change significantly,and the smoke tends to spread down under the action of the sprinkler,which causes the smoke to accumulate in the lower space.The full-size FDS numerical simulation method is employed to study the law of the corridor fire development under sprinkler action.With the decrease in the distance between the sprinkler and the fire source,some high-temperature smoke is difficult to discharge the corridor space through natural-smoke-exhaust;At the beginning of the corridor fire,the sprinkler can reduce the temperature of the fire field and the spread of smoke flow,however,with the development of the fire,it is easy to cause the decrease of the smoke layer height,the visibility of the bottom area of the corridor,and the smoke exhaust efficiency,which threatens the escape of the trapped persons.