Analysis on the influence of fire resistance time of Henan fire rolling shutter door on the coming of fire danger

In the fire protection design of buildings, ensuring the safe evacuation of people is the primary premise of fire protection design, and the important standard of fire safety evacuation is time. China has made detailed regulations on the setting of evacuation width, evacuation distance, various fire-fighting facilities and other elements in various fire technical specifications. These are hard standards for fire design and review, but in fact, these requirements are not isolated from each other and created out of thin air. They all serve to ensure the safe evacuation of people, The setting requirements in the specification mostly come from the calculation of the fire safety evacuation time, so understanding the fire safety evacuation time is the basis and premise for the design and installation of fire rolling shutter doors.

The so-called safe evacuation of Henan fire shutter door refers to the evacuation of people to a safe area before the fire develops to threaten the safety of people, that is, to make the safe evacuation time less than the time of danger, which is the benchmark of evacuation design, and all other design elements should serve this goal.

In a fire, the main factors that can cause danger to people are high temperature, toxic smoke, building structure collapse and so on. The high temperature is mainly caused by thermal convection and radiation. When the air temperature reaches 100 ℃, ordinary people can only endure it for more than 10 minutes. When the temperature exceeds 200 ℃, people will die within 5 minutes. The harmful gases in the smoke mainly include carbon monoxide, carbon dioxide, formaldehyde, acetaldehyde, hydrogen cyanide, etc. The common carbon monoxide content in the air as long as 1%, people will lose consciousness after breathing several times, which will lead to death. At present, a large number of polyethylene, polystyrene and other building materials will produce toxic smoke after combustion. Smoke will not only cause poisoning, but also reduce the visibility of people in dense smoke due to the dimming effect of smoke. When the visibility is less than 0.5m, the moving speed of people is equivalent to the walking speed when they lose their vision. Henan fireproof rolling shutter door usually has a fire resistance limit much higher than the time of smoke spreading and flowing, but if flammable and combustible decoration materials are used in the evacuation passageway, it may also burn rapidly.