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Fire hazard of underground garage in buildings

The fire spreads quickly

The underground garage has a small opening area and poor smoke exhaust and heat dissipation. Once a fire occurs, it will cause the accumulation of hot smoke, slow heat dissipation, and the internal space temperature will rise. The indoor air volume will also increase, which is prone to explosion. In the early stages of an underground garage fire, the airflow and smoke in the passage will flow in the original direction of diffusion. As the fire spreads, the air composition inside the tunnel will change, the temperature will increase, and additional fire air pressure will be formed, causing the original airflow direction to change and the original wind pressure to increase. Some of the smoke that has reached the exit will turn back into the tunnel, and in severe cases, jumping fire points may occur, leading to further spread of the fire.

Difficulty in ventilation and smoke exhaust

Underground garages are different from ground level buildings. In case of a fire, smoke exhaust and heat dissipation can only be achieved through entrances and exits connected to the ground or skylights, resulting in poor ventilation conditions. Moreover, after a fire occurs in the underground garage, there is insufficient air for the combustion of substances, and over time, there will be significant smoke and toxic gases produced. Moreover, these smoke and toxic gases cannot be * * eliminated from the underground garage space, and they fill the entire underground space, posing a serious threat to the lives of personnel.

Difficulty in evacuation

There are no windows or balconies in the underground garage, so in case of a fire, evacuation can only be done through the * * exit. When a fire occurs, the normal power supply is cut off, and the role of accident lighting and evacuation sign indicator lights is very limited in the thick smoke state. The visibility is low, and some personnel cannot even identify the direction of escape, making evacuation difficult. Moreover, underground garages usually have a large depth and complex layout, and the panic caused by emergency evacuation can prolong the evacuation time and increase the danger. In addition, due to the fact that the evacuation direction of personnel is consistent with the direction of smoke spread, it is impossible to escape the influence of smoke during the evacuation process.