The fire spread quickly.

Because of the small orifice area of underground garage, the smoke exhaust and heat dissipation performance is poor, the hot smoke can not be dispersed, and the heat dissipation is slow, and the internal space temperature suddenly rises, reaching 800 ~ 900 E, even exceeding1000 E; The indoor air volume has also increased by 1 ~ 2 times, and the pressure has also increased accordingly. The underground garage covers an area of about 2,000 ~ 3,000 m2, which is large and connected from top to bottom. In addition, a large number of synthetic materials, mainly polyurethane, are used in automobile interiors, which not only burns quickly, but also releases a lot of heat and toxic smoke during the combustion process. Therefore, once a fire breaks out, it is easy to form a domino effect, causing a large-scale fire to get out of control and directly threatening the safety of the building itself.

When the internal temperature of the underground garage rises above 400e, the fire will change from local combustion to complete combustion in an instant, and the indoor temperature will soar from 400e to 800 ~ 900 E. Research shows that the underground garage fire is more prone to flashover than the ground building fire, and it appears earlier. At the beginning of the fire, the airflow and smoke in the passage flow in the original diffusion direction.

ask

According to Article 5. 1. 1 and Article 5. 1.2 of this specification, the maximum fire zone area is 4000 square meters. According to the fire protection code, the evacuation exit of the underground garage fire zone must have its own exit. The nearby fire zone can be used as another evacuation exit, but it still needs to be in accordance with the requirements of the local fire department.

Fire partition refers to the area separated by firewall, floor, fire door or fire shutter, which can limit the fire to a certain local area (within a certain period of time) to prevent the fire from spreading. Of course, the partition of the fire zone also plays a role in isolating smoke.