Fire characteristics of the hottest high-rise buil

Fire characteristics of high-rise buildings

some fire cases of high-rise buildings at home and abroad show that the main characteristics of high-rise building fires are rapid spread, strong chimney effect, easy to spread upward rapidly, several floors burn at the same time, forming a three-dimensional fire, and the harm of hot smoke and toxic gas is serious, which directly threatens people's life safety. Once the fire in high-rise buildings is out of control, it will lead to a huge fire

1. There are many ways for smoke and fire to spread, which is easy to form three-dimensional fires

(1) vertical tube wells, shared spaces, glass curtain wall cracks and other parts of high-rise buildings are easy to produce "chimney" effect, resulting in rapid spread of smoke and fire. In the development stage, its vertical spreading speed is m/s. (2) Smoke and fire are easy to spread along the ceiling door. 2. The negative deviation of the indication is out of tolerance, and the windows and walkways spread horizontally. In the development stage, its horizontal spread rate is 0 8m/s。 (3) The fire rose and curled up along the outer wall window, and even jumped to the upper floor. (4) The external wind force will cause the adjacent buildings to burn. (5) Prone to deflagration. Five to seven minutes after a fire in a high-rise building, as the combustion time continues, the room temperature continues to rise, and the oxygen rapidly decreases. By 2018, the high heat indoors will make the combustible gas reaching the limit of explosive concentration reach more than 600 ℃. If fresh air enters the outside, an annual compound growth rate of 3.7% deflagration will occur

2. It is difficult to evacuate, which is very easy to cause casualties

(1) when a fire occurs in a high-rise building, people often panic and crowd, which is easy to cause trampling injury and death, and even people jumping out of the building. For example, on April 19, 1985, the swan hotel fire in Harbin killed as many as 9 people by jumping off the building. (2) High temperature and smoke fill the building, reducing visibility, which is easy to cause panic among trapped people and increase the difficulty of safe evacuation. Personnel may faint after staying in the thick smoke for min, and there is a danger of death after min. (3) Smoke, toxic gas and other combustion products are very easy to cause suffocation and poisoning death. A large number of statistics at home and abroad show that more than 50% of the deaths in high-rise building fires are poisoned by smoke

for example, on May 13, 1972, a fire broke out in the Qianri department store in Osaka, Japan, killing 118 people, of whom 93 died of suffocation and poisoning. About 80%. (4) Burned to death. People in high-rise buildings who enhance their strategic thinking ability are often burned to death after suffocation due to smoke poisoning; Or burned to death in his sleep; Or the route was improperly selected during the escape, and the escape route was blocked by fireworks and burned to death

in high-rise buildings, thermal convection is the main form of fire spread, fire wind pressure and chimney effect are the driving forces of fire spread, and high-temperature hot smoke above 500 ℃ is the condition of fire spread