principle of fire zone

from the point of view of fire prevention, the smaller the fire zone is, the better it is to ensure the fire safety of buildings. However, if the division is too small, it will inevitably affect the use function of the building, which is obviously not feasible. The determination of the area of fire protection zone should consider the use nature, importance, fire risk, building height, fire fighting ability and fire spreading speed of buildings.

China's current Code for Fire Protection Design of Buildings, Code for Fire Protection Design of Civil Air Defense Engineering, etc. all stipulate the fire protection zoning area of buildings, and must be strictly implemented in combination with the actual project when designing, auditing and checking. Fire partition of civil buildings

5.3 Fire partition and number of floors

5.3.1 Unless otherwise specified in this specification, the allowable building height or number of floors and the maximum allowable building area of fire partition of buildings with different fire resistance grades shall comply with the provisions in Table 5.3.1.

table 5.3.1 allowable building height, number of floors and maximum allowable building area of fire zone for buildings with different fire resistance grades

note: the maximum allowable building area of fire zone specified in table 1 can be increased by 1.1 times when an automatic fire extinguishing system is installed in the building; In case of local setting, the increased area of the fire zone can be calculated as 1.1 times of the local area.

2 when a firewall is installed between the podium and the main body of a high-rise building, the fire zone of the podium can be determined according to the requirements of single-storey and multi-storey buildings.

5.3.2 when escalators, open stairs and other openings are set in the building, the construction area of the fire zone should be calculated by adding the construction areas of the upper and lower floors to Unicom; When the construction area after superposition calculation is greater than the provisions of Article 5.3.1 of this specification, fire zones shall be divided.

when an atrium is set up in a building, the building area of its fire zone should be calculated by adding the building areas connected with the upper and lower floors; When the building area after superposition calculation is greater than the provisions in Article 5.3.1 of this specification, the following provisions shall be met:

1 The connected space with the surrounding area shall be separated by fire: when a fire partition wall is adopted, its fire resistance limit shall not be less than 1.11 h; When using fire-proof glass wall, its fire insulation and fire integrity should not be less than 1.11h, and when using non-thermal fire-proof glass wall with fire integrity not less than 1.11h, automatic sprinkler system should be set up for protection; When using fire shutter, its fire resistance limit should not be less than 3.11h, and should comply with the provisions of Article 6.5.3 of this specification; The doors and windows communicating with the atrium shall be Class A fire doors and windows that can be closed automatically in case of fire;

2 The atrium cloister in the high-rise building should be equipped with automatic sprinkler system and automatic fire alarm system;

3 the atrium should be equipped with smoke exhaust facilities;

4 combustible materials should not be arranged in the atrium.

5.3.3 fire partitions should be separated by fire partition walls, and when it is really difficult, fire shutter and other fire separation facilities can be used for separation. When using fire shutter to separate, it shall comply with the provisions of Article 6.5.3 of this specification.

5.3.4 When automatic fire extinguishing system and automatic fire alarm system are installed in shops, business halls and exhibition halls in buildings with first-class and second-class fire resistance, and nonflammable or nonflammable decoration materials are used, the maximum allowable building area of each fire zone shall meet the following requirements:

1 When it is installed in a high-rise building, it shall not be greater than 4,111m2;

2 when it is installed in a single-storey building or only in the first floor of a multi-storey building, it should not be greater than 11111 ㎡;

3 when it is set underground or semi-underground, it should not be greater than 2111m2.

5.3.5 Underground or semi-underground shops with a total construction area of more than 21,111 ㎡ should be divided into multiple areas with a construction area of not more than 21,111 ㎡ by using a firewall without doors, windows and holes and a floor with a fire resistance limit of not less than 2.11h h.. When local communication between adjacent areas is really necessary, outdoor open spaces such as sunken plaza, fire compartments, evacuation walkways and smoke-proof stairwells should be used for communication, and the following requirements should be met:

1 Outdoor open spaces such as sunken plaza should be able to prevent fire spread in adjacent areas and facilitate safe evacuation, and should comply with the provisions of Article 6.4.12 of this specification;

2 The wall of the fire compartment shall be a fire partition with a fire resistance limit of not less than 3.11h, and shall comply with the provisions of Article 6.4.13 of this specification;

3 the evacuation walkway shall comply with the provisions of article 6.4.14 of this specification;

4 The doors of smoke-proof stairwells should adopt Class A fire doors.

5.3.6 commercial facilities such as restaurants and shops are linked through a covered pedestrian street, and buildings on both sides of the pedestrian street need to be evacuated safely, the following requirements shall be met:

1 The fire resistance rating of buildings on both sides of the pedestrian street shall not be lower than Grade II.

2 The nearest distance from the buildings on both sides of the pedestrian street to the opposite side should not be less than the fire prevention distance of buildings with corresponding height in this specification and should not be less than 9m. The end of the pedestrian street should not be closed on all floors. If it is really necessary to close, doors and windows that can be opened should be set on the external wall, and the area of the doors and windows that can be opened should not be less than half of the external wall area of this part. The length of pedestrian street should not be greater than 311m m.

3 fireproof partitions with a fire resistance limit of not less than 2.11h should be set between the shops on both sides of the pedestrian street, and the construction area of each shop should not be greater than 311m2.

4 For the shops on both sides of the pedestrian street, the fire resistance limit of the enclosure components on the side facing the pedestrian street should not be less than 1.11h, and solid walls should be adopted, and the doors and windows should be Class B fire doors and windows; When using fire-proof glass walls (including doors and windows), their fire insulation and fire integrity should not be less than 1.11 h; When non-thermal fire-proof glass walls (including doors and windows) with fire integrity not less than 1.11h are used, a closed automatic sprinkler system shall be set for protection. A solid wall with a width of not less than 1.1m and a fire resistance limit of not less than 1.11h should be set on the side facing the pedestrian street between adjacent shops.

when the buildings on both sides of the pedestrian street are multiple floors, the shops on one side of the pedestrian street on each floor shall be provided with measures to prevent the vertical spread of fire, and shall comply with the provisions of Article 6.2.5 of this specification; When setting cloisters or overhangs, the overhanging width should not be less than 1.2m；; When the shops on both sides of the pedestrian street need to set up corridors and connecting overpasses on the upper floors, the opening area of the upper floors of the pedestrian street should be ensured to be not less than 37% of the ground area of the pedestrian street, and the openings should be evenly arranged.

5 the evacuation stairs in the buildings on both sides of the pedestrian street should be set by the external wall and should be directly connected to the outdoor. If there is any difficulty, they can be directly connected to the pedestrian street on the first floor; The evacuation doors of the shops on the first floor can directly lead to the pedestrian street, and the walking distance from any point in the pedestrian street to the nearest outdoor safe place should not be more than 61m. The straight-line distance between the evacuation doors of shops on the second floor and above of buildings on both sides of the pedestrian street and the nearest evacuation stairs or other safety exits on this floor should not be greater than 37.5m m.

6 The ceiling material of the pedestrian street should be incombustible or nonflammable, and the fire resistance limit of its load-bearing structure should not be less than 1.11h h.. Combustible materials should not be arranged in the pedestrian street.

7 The height between the lower eaves of the ceiling of the pedestrian street and the ground should not be less than 6.1m The ceiling should be provided with natural smoke exhaust facilities and normally open smoke exhaust ports should be adopted, and the effective area of natural smoke exhaust ports should not be less than 25% of the ground area of the pedestrian street. Normally closed natural smoke exhaust facilities should be able to be opened manually and automatically in case of fire.

8 DN65 fire hydrants should be set outside the shops on both sides of the pedestrian street at intervals of 31m, and fire hose reels or fire hoses should be equipped; automatic sprinkler systems and automatic fire alarm systems should be set inside the shops; Each corridor should be equipped with automatic sprinkler system. The pedestrian street should be equipped with automatic tracking and positioning jet fire extinguishing system.

9 Evacuation lighting, light evacuation signs and fire emergency broadcasting system should be set inside and outside the shops of buildings on both sides of the pedestrian street. Fire zone of workshop and warehouse

3.3 Floor, area and plane layout of workshop and warehouse

3.3.1 Unless otherwise specified in this specification, the floor number of workshop and the maximum allowable building area of each fire zone shall comply with the provisions in Table 3.3.1

Table 3.3.1 Floor number of workshop and the maximum allowable building area of each fire zone

Note: 1 There shall be two fire zones. In addition to the Class A workshop, the single-storey workshop with the first and second fire resistance rating can be separated by fire shutter or fire separation water curtain when the building area of its fire partition is larger than that specified in this table and it is indeed difficult to set up a firewall. When using fire shutter, it shall comply with the provisions of Article 6.5.3 of this specification; When the water curtain is separated by fire prevention, it should comply with the relevant provisions of the current national standard "Code for Design of Automatic Sprinkler Fire Extinguishing System" GB51184.

2 the maximum allowable building area of each fire zone can be increased by 1.5 times according to the regulations in this table, except for the linen workshop. However, the raw cotton unpacking and flower cleaning workshop in the workshop should be separated from other parts of the workshop by a fire partition wall with a fire resistance limit of not less than 2.5h When doors, windows and holes need to be opened, Class A fire doors and windows should be set.

3 the maximum allowable building area of each fire zone of a single-layer and multi-layer paper-making joint factory building with first-class and second-class fire resistance rating can be increased by 1.5 times as specified in this table. When the automatic fire extinguishing system is installed in the dryer cover of the paper machine and the effective fire extinguishing facilities are installed in the workshop section, the maximum allowable building area of each fire zone can be determined according to the process requirements.

4 The working tower of grain silo with first-class and second-class fire resistance, when the number of workers on each floor is less than 2, the number of floors is not limited;

5 The production rooms of raw materials, materials preparation and group formula, silk making, silk storage and wrapping, auxiliary materials turnover, temporary storage of finished products, carbon dioxide expanded cut tobacco, etc. in the first and second-class fire-resistant cigarette production joint workshop should be divided into independent fire-proof separation units, and when the process conditions permit, they should be separated by firewalls. Among them, the workshop of silk making, silk storage and wrapping can be divided into a fire zone, and the maximum allowable building area of each fire zone can be determined according to the process requirements. However, the workshops of silk making, silk storage and wrapping should be separated by a wall with a fire resistance of not less than 2.11h and a floor with a fire resistance of 1.11h h.. Measures should be taken to prevent the spread of fire in the openings of horizontal and vertical compartments in the factory building.

6 when the number of users of the operation platform and maintenance platform in the factory building is less than 11, the area of the platform may not be included in the building area of the fire zone.

7 "-"means not allowed.

3.3.2 unless otherwise specified in the sub-specification, the number of storeys and the area of the warehouse shall comply with the provisions in table 3.3.2.

Table 3.3.2 Number of storeys and area of warehouses

Note: 1 Fire partitions in warehouses must be separated by firewalls, and doors, windows and holes should not be opened in the firewalls between fire partitions in Class A and Class B warehouses; The maximum allowable floor area of underground or semi-underground warehouses (including underground or semi-basement) shall not be greater than that of the above-ground warehouses of corresponding categories.

2 the barreled oil product warehouse in the roommate's reservoir area shall comply with the current national standard "Code for Design of Petroleum Depots" GB 51174.

3 the maximum allowable building area of each fire protection zone of the coal homogenizing silo with first-class and second-class fire resistance should not be greater than 1.2111m2.

4 independently built ammonium nitrate warehouses, calcium carbide warehouses, polyethylene and other polymer products warehouses, urea warehouses, coal blending warehouses, and independent finished product warehouses in paper mills, when the fire resistance rating of the buildings is not lower than Grade II, the maximum allowable floor area of each warehouse and the maximum allowable building area of each fire zone can be increased by 1.1 times according to the provisions in this table.

5. The maximum allowable floor area of the first-class and second-class fire-resistant grain warehouse should not be greater than 1.2111m2, and the maximum allowable building area of each fire zone should not be greater than 3,111m2; The maximum allowable floor area of grain warehouse with three-level fire resistance should not be greater than 3,111 ㎡, and the maximum allowable building area of each fire zone should not be greater than 1,111 ㎡

6 For single-layer cotton warehouse with one-level and two-level fire resistance and an area of not more than 2,111 ㎡, the maximum allowable building area of its fire zone should not be greater than 2,111 ㎡.

7 the maximum allowable floor area and the maximum allowable building area of the first-class and second-class fire-resistant cold storage should comply with the current national standard "Code for Design of Cold Storage" GB 51172.

8 "-"means not allowed.

3.3.3 when an automatic fire extinguishing system is installed in the factory building, the maximum allowable building area of each fire zone can be increased by 1.1 times according to the provisions in Article 3.3.1 of this specification. When the automatic fire extinguishing system is installed in the workshop on the site of Class D and E, the maximum allowable building area of each fire zone is not limited. When an automatic fire extinguishing system is installed locally in the factory building, the increased area of the fire protection zone can be calculated as 1.1 times of the local area.

when an automatic fire extinguishing system is installed in the warehouse, the maximum allowable floor area of each warehouse and the maximum allowable building area of each fire zone can be increased by 1.1 times according to the provisions of Article 3.3.2 of this specification, except for the fire zone of the cold storage.

3.3.4 Class A and B production sites (warehouses) should not be located underground or semi-underground.

3.3.5 it is forbidden to set the staff dormitory in the factory building.

offices, lounges, etc. should not be located in Class A and Class B factories. When it is really necessary to stick to this factory, its fire resistance rating should not be lower than Class II, and it should be separated from the factory by explosion-proof walls with a fire resistance limit of not less than 3.11h, and independent safety exits should be set up.

when the office and lounge are set in a class c factory building, a fireproof partition wall with a fire resistance limit of not less than 2.5h and a floor of 1.11h should be used to separate them from other parts, and at least 1 independent safety exits should be set. If interconnected doors need to be opened on the partition wall, Class B fire doors should be adopted.

3.3.6 When intermediate warehouses are set up in the factory building, the following requirements shall be met:

1 Class A and Class B intermediate warehouses shall be arranged by external walls, and their reserves shall not exceed the demand for 1 days and nights;

2 Class A, B and C intermediate warehouses should be separated from other parts by firewall and incombustible floor with fire resistance not less than 1.5h;

3 The intermediate warehouses of Class D and E should be separated from other parts by fireproof partition walls with a fire resistance limit of not less than 2.11h and a floor slab of 1.11h;

4 the fire resistance grade and area of the warehouse shall comply with the provisions of articles 3.3.2 and 3.3.3 of this specification.

3.3.7 The intermediate storage tank of Class C liquid in the plant should be set in a separate room, and its capacity should not be more than 5m? . The room with the intermediate storage tank shall be separated from other parts by a fireproof partition wall with a fire resistance limit of not less than 3.11h and a floor of 1.51h, and the room door shall be a Class A fireproof door.

3.3.8 transformer and distribution stations should not be located in or adjacent to Class A and B workshops, and should not be located in dangerous areas with explosive gas and dust environment. Substations of 11kv and below dedicated for Class A and Class B workshops can be attached on one side when separated by a firewall without doors, windows and holes, and should comply with the current national standard "Code for Design of Electrical Devices in Explosive Hazardous Environments" GB 51158 and other standards.

when it is really necessary to open windows on the firewall in the power distribution station of class b workshop, class a fire windows should be adopted.

3.3.9 it is forbidden to set the staff dormitory in the warehouse.

office