4.6.3 Except for the atrium, the calculation of smoke exhaust volume of smoke-proof partition walls in the following places shall meet the following requirements:
1 For places with clear height of building space less than or equal to 6m, the smoke exhaust quantity shall be calculated as not less than 60m3/(h m2), and the value shall be not less than 15000m3? /h, or set up a natural smoke exhaust window (mouth) with an effective area not less than 2% of the building area of the room.
2 For places with a clear height of more than 6m in public buildings and industrial buildings, the smoke exhaust quantity of each smoke-proof partition shall be calculated and determined according to the heat release rate of the place and the provisions in Articles 4.6.6 to 4. 6. 5438+03 of this standard, and shall not be less than the value in Table 4.6.3, or natural smoke exhaust windows (openings) shall be set, and the required effective smoke exhaust area shall conform to the table.
2 When natural smoke exhaust is used, the thickness of the smoke storage bin should be greater than 20% of the clear height of the room; Area (mouth) of natural smoke exhaust window = calculated smoke exhaust volume/wind speed (mouth) at natural smoke exhaust window; When the top window exhausts smoke, the wind speed of the natural smoke exhaust window (mouth) can be calculated as 1.4 times of the wind speed of the side window.
3 When public buildings only need to set smoke exhaust in corridors or corridors, the mechanical smoke exhaust volume should not be less than 13000m3/h, or natural smoke exhaust windows (openings) with an area of not less than 2m2 should be set at both ends (both sides) of the corridor, and the distance between natural smoke exhaust windows (openings) on both sides should not be less than 2/3 of the length of the corridor.
4 When the rooms, walkways or cloisters of public buildings need to be provided with smoke outlets, the mechanical smoke exhaust capacity of the walkways or cloisters can be calculated as 60m3/(h m2) and not less than 13000m3/h, or a natural smoke exhaust window (outlet) with an effective area not less than 2% of the building area of the walkways and cloisters can be provided.
4.6.4 When a smoke exhaust system is responsible for the smoke exhaust of multiple smoke prevention zones, the calculation of smoke exhaust volume of the system shall meet the following requirements:
1 When the system is responsible for places with the same clear height, for places with a clear height of building space greater than 6m, the smoke exhaust quantity of a smoke-proof partition with the largest smoke exhaust quantity shall be calculated; Where the clear height between buildings is 6m or less, it shall be calculated according to the maximum sum of smoke exhaust of any two adjacent smoke prevention zones in the same fire prevention zone.
2 When the system has the burden of places with different clear heights, the above method should be used to calculate the smoke exhaust required by each place in the system, and the maximum value should be taken as the smoke exhaust of the system.
4.6.5 The design and calculation of atrium smoke exhaust shall meet the following requirements:
1 Smoke exhaust system is set around the atrium. When mechanical smoke exhaust system is used in the atrium, the smoke exhaust quantity of the atrium should be calculated as twice the maximum smoke exhaust quantity of the surrounding smoke-proof partition, and should not be less than107000m3/h; When natural smoke exhaust system is used in atrium, the effective window area should be calculated according to the above smoke exhaust amount and the wind speed of natural smoke exhaust window (mouth) is not more than 0.5m/s.
2 There is no need to set up a smoke exhaust system in the places around the atrium. Only when a smoke exhaust system is set up in the cloister, the smoke exhaust capacity of the cloister should not be less than the provisions in Paragraph 3 of Article 4.6.3 of this standard, and the smoke exhaust capacity of the atrium should not be less than 40,000m3/h; When natural smoke exhaust system is used in atrium, the effective window area should be calculated according to the above smoke exhaust amount and the wind speed of natural smoke exhaust window (mouth) is not more than 0.4m/s.