Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
According to the requirements of Document JIANBIAO [2006] No.77 issued by the Ministry of Housing and Urban-Rural Development of the People's Republic of China - Notice on printing and distributing the development and revision plan on engineering construction standards and codes in 2006 (first batch), this standard is formulated by the Sichuan Fire Research Institute of Ministry of Public Security jointly with Shanghai Public Security Fire Corps and other organizations concerned.
In the process of formulating this standard, the drafting group, following the relevant national laws, regulations and technical standards, thoroughly investigated the design and engineering application of the smoke protection and exhaust systems in buildings, carefully summarized the fire accident lessons and the engineering application practice of smoke protection and exhaust systems in buildings, referred to the domestic and foreign relevant standards and codes, adopted the advanced scientific research achievements, extensively solicited the opinions of design, supervision, construction, product manufacture, fire supervision and other relevant units, and finalized this standard through review.
The standard consists of 9 clauses and 7 annexes, with the main technical contents as follows: General provisions, Terms and symbols; Smoke protection system design, Smoke exhaust system design, System control, System construction, System commissioning, System acceptance, Maintenance management, etc.
The provisions printed in bold type in this standard are compulsory and must be enforced strictly.
The Ministry of Housing and Urban-Rural Development of the People's Republic of China is in charge of the administration of this standard and the explanation of the compulsory provisions, the Fire Department of Ministry of Public Security is in charge of routine management, and Sichuan Fire Research Institute of Ministry of Public Security is responsible for the explanation of specific technical contents. During the process of implementing this standard, all relevant organizations are kindly requested to sum up experience and accumulate information carefully in combination with engineering practice, and feed the relevant opinions and suggestions back to Sichuan Fire Research Institute of Ministry of Public Security (address: No.69, Jinke South Road, Jinniu District, Chengdu City, Sichuan Province, 610036, China) for future reference in revision.
Contents
1 General provisions 1
2 Terms and symbols 2
2.1 Terms 2
2.2 Symbols 4
3 Smoke protection system design 8
3.1 General requirements 8
3.2 Natural ventilation facilities 10
3.3 Mechanical pressurization facilities 10
3.4 Calculation of air volume in mechanical pressurization system 13
4 Smoke exhaust system design 18
4.1 General requirements 18
4.2 Smoke control zone 19
4.3 Natural smoke exhaust facilities 20
4.4 Mechanical smoke exhaust facilities 22
4.5 Air makeup system 26
4.6 Calculation of smoke exhaust system 27
5 System control 35
5.1 Smoke protection system 35
5.2 Smoke exhaust system 35
6 System construction 38
6.1 General requirements 38
6.2 Field inspection 39
6.3 Air duct installation 42
6.4 Duct accessory installation 45
6.5 Fan installation 47
7 System commissioning 49
7.1 General requirements 49
7.2 Single machine commissioning 49
7.3 Linked commissioning 52
8 System acceptance 54
8.1 General requirements 54
8.2 Project acceptance 54
9 Maintenance management 58
Annex A Mechanical exhaust smoke volume of different fire sizes 59
Annex B Maximum allowable smoke exhaust volume at the smoke exhaust inlet 61
Annex C Classification of subsection and subitem works in smoke protection and exhaust systems 64
Annex D Quality inspection records during construction 65
Annex E Inspection records for project quality control data of smoke protection and exhaust systems 69
Annex F Inspection records for smoke protection and exhaust project 70
Annex G Inspection items for maintenance management of smoke protection and exhaust systems 72
Explanation of wording in this standard 73
List of quoted standards 74
1 General provisions
1.0.1 This standard is formulated with a view to rationally designing the smoke protection and exhaust systems, guaranteeing the construction quality, regulating the acceptance and maintenance management, reducing fire hazard and protecting personal and property safety.
1.0.2 It is applicable to the design, construction, acceptance and maintenance management of smoke protection and exhaust systems in the constructed, extended and renovated industrial and civil buildings. For the industrial and civil buildings for special purposes or with special requirements, the special requirements, if any, specified in the professional standards, may be followed.
1.0.3 The design of smoke protection and exhaust systems in buildings shall be safe, reliable, technologically advanced and economically reasonable by taking effective technical measures in combination with factors such as the characteristics and the fire smoke development law of buildings.
1.0.4 The equipment of the smoke protection and exhaust systems in buildings shall be the products in conformity with relevant current standards of the nation and the relevant access systems.
1.0.5 In addition to this standard, the design, construction, acceptance and maintenance management of smoke protection and exhaust systems in buildings shall also meet the requirements of the current relevant standards of the nation.
2 Terms and symbols
2.1 Terms
2.1.1 smoke protection system
system used for preventing the fire smoke from accumulating in the spaces such as stairwell, anteroom, refuge floor (room) in the manner of natural ventilation or preventing the fire smoke from entering the spaces such as stairwell, anteroom, refuge floor (room) in the manner of mechanical pressurization, which is classified into natural ventilation system and mechanical pressurization system
2.1.2 smoke exhaust system
system used for exhausting the fire smoke from the room, walkway and other spaces to the outdoors in the manner of natural smoke exhaust or mechanical smoke exhaust, which is classified into natural smoke exhaust system and mechanical smoke exhaust system
2.1.3 mechanical pressurization without air shaft
a kind of air supply mode directly applying mechanical pressurization for stairwell with fan, without using any air shaft
2.1.4 natural smoke exhaust
a kind of smoke exhaust mode directly exhausting the smoke to the outdoors through the building openings by using the buoyancy of hot fire smoke flow and the external wind pressure
2.1.5 natural smoke vent
openable exterior window or opening with smoke exhaust function, which can be opened automatically, manually or in thermal release or other modes
2.1.6 smoke plume
mixed smoke flow formed by fire smoke entraining the surrounding air, which may be classified into axisymmetric plume, balcony spill plume, window plume, etc. according to the flow condition of flame and smoke
2.1.7 axisymmetric plume
plume that does not contact with the surrounding walls or obstacles and is not disturbed by air flow
2.1.8 balcony spill plume
plume which spills from the door (window) beam of the room on fire, flows along the balcony or horizontal projections outside the room on fire, and overflows upwards to the spill to the adjacent tall space along the edge of balcony or horizontal projections
2.1.9 window plume
plume which spills from the openings such as door and window of the room or compartment on ventilation-limited fire to the adjacent tall space
2.1.10 draft curtain
a kind of smoke obstruction facility which is made of non-combustible material and is installed vertically under the roof, beam or suspended ceiling to form a certain smoke storage space in case of fire
2.1.11 smoke reservoir
a space located at the top of the building space and consisting of draft curtain, beam or a partition wall to reserve the fire smoke, of which the height is the design depth of the smoke layer
2.1.12 clear height
the height from the lower edge of the smoke layer to the indoor floor
2.1.13 mass flow rate of plume
the mass of the plume flowing through a horizontal section at a certain height per unit time, expressed in kg/s
2.1.14 combination fire and smoke damper
damper which is installed in the duct of mechanical smoke exhaust system, is normally open, but is closed when the smoke temperature in exhaust duct reaches 280℃ in case of fire and is capable of meeting the smoke leakage amount and fire integrity requirements within a certain time to prevent the smoke and fire, and is generally composed of damper body, blade, actuator, temperature sensor and other components
2.1.15 smoke damper
damper which is installed at the end (smoke suction inlet) of each branch duct of the mechanical smoke exhaust system, is normally closed and meets the smoke leakage amount requirements, and can be manually and electrically opened and closed to exhaust smoke in case of fire and is generally composed of damper body, blade, actuator and other components
2.1.16 smoke exhaust inlet
the smoke inlet in the mechanical smoke exhaust system
2.1.17 fixed window for fire forcible entry
exterior window arranged in the place without mechanical smoke protection and exhaust systems, of which the sashes are fixed and normally closed, and are easy to manually disassembled in case of fire to exhaust the smoke and heat from the fire field
2.1.18 fusible daylighting band
a facility made of the material that melts at 120℃ to 150℃ and does not produce droplets, which is placed in the upper part of the building to exhaust the smoke and heat from the fire field
2.1.19 independent anteroom
an anteroom that is only connected to an escape stairway
2.1.20 shared anteroom
an anteroom that is shared by two scissor stairwells (in residential building)
2.1.21 combined anteroom
an anteroom that is a combination of the anteroom of smoke-proof stairwell and anteroom of fire elevator
2.2 Symbols
2.2.1 Calculating geometric parameters
A——the effective air leakage area of each evacuation door;
Ak——the sectional area of an opening door;
A0——the total area of all air intakes;
Am——the area of a door;
Af——the area of a single air supply valve;
Ag——the total area of evacuation doors in anterooms;
Al——the total area of evacuation doors in stairwells;
Av——the sectional area of natural smoke vent;
Aw——the window opening area;
B——the long side size of air duct;
b——the distance from the opening to the edge of the balcony;
dm——the distance from the handle to the latch of the door;
db——the depth of the smoke layer below the lowest point of the suction inlet of smoke exhaust system;
D——the diameter of the air duct;
H——the net height of the space;
H′——the net height of the building in smoke exhaust space for single-storey space and the storey height of the highest evacuation floor for multi-storey space;
Hl——the height from the fuel surface to the balcony;
Hw——the window opening height;
Hq——the minimum clear height;
ω——the opening width of the fire source area;
W——the diffusion width of the plume;
Wm——the width of a single-leaf door;
Z——the height from the fuel surface to the bottom of the smoke layer;
Zl——the limit height of flame;
Zb——the height from the lower edge of the balcony to the bottom of the smoke layer;
Zw——the height from the upper edge of the window opening to the bottom of the smoke layer.
2.2.2 Calculating air volume and speed
g——the gravitational acceleration;
Lhigh——the allowable air leakage per unit time of the air duct per unit area in the high-pressure system;
Lj——the mechanical pressurization air supply volume of stairwell;
Llow——the allowable air leakage per unit time of the air duct per unit area in the low-pressure system;
Lmid——the allowable air leakage per unit time of the air duct per unit area in the middle-pressure system;
Ls——the mechanical pressurization air supply volume of anteroom;
L1——the air supply volume required to reach the specified air speed when the door is opened;
L2——the total air leakage volume of other door slots under the specified air speed value when the door is opened;
L3——the total air leakage volume of the normally closed air supply valve that is not opened;
Mρ——the mass flow rate of plume;
v——the air speed in the cross section of door opening;
V——the smoke exhaust volume;
Vmax——the maximum allowable smoke exhaust volume at the smoke exhaust inlet.
2.2.3 Calculating pressure, heat quantity and time
Cp——the specific heat of air at constant pressure;
F′——the total thrust of door;
Fdc——the force required to overcome the door closer at the door handle;
M——the opening moment of door closer;
ρ0——the gas density at ambient temperature;
P——the maximum allowable pressure difference of the evacuation door;
Pair duct——the working pressure of duct system;
ΔP——the average pressure difference for calculating the air leakage volume;
Q——the heat release rate;
Qc——the convection section of heat release rate;
t——the fire growth duration;
T——the average absolute temperature of the smoke layer;
T0——the absolute temperature of the environment;
△T——the difference between the average temperature of the smoke layer and the ambient temperature.
2.2.4 Calculation coefficients
α——the fire growth coefficient;
αw——the correction coefficient of window plume;
γ——the position coefficient of smoke exhaust;
C0——the flow coefficient of air intake;
Cv——the flow coefficient of natural smoke vent;
K——the convective heat release factor in the smoke;
n——an index.
2.2.5 Other calculating symbols
N1——the number of floors on which the evacuation door is designed to be open;
N2——the number of air-leaking evacuation doors;
N3——the number of air-leaking valves.
3 Smoke protection system design
3.1 General requirements
3.1.1 The design of smoke protection system in building shall adopt natural ventilation system and mechanical pressurization system according to factors such as the height and use nature of the building.
3.1.2 For the public and industrial buildings with building height of more than 50m and the residential buildings with building height of more than 100m, the mechanical pressurization system shall be adopted for their smoke-proof stairwell, independent anteroom, shared anteroom, combined anteroom and fire elevator anteroom.
3.1.3 For the public and industrial buildings with building height of less than or equal to 50m and the residential buildings with building height of less than or equal to 100m, the natural ventilation system shall be adopted for their smoke-proof stairwell, independent anteroom, shared anteroom, combined anteroom (except for the combination of shared anteroom and fire elevator anteroom) and fire elevator anteroom; mechanical pressurization system shall be adopted when the natural ventilation system cannot be arranged. The selection of smoke protection system shall also meet the following requirements:
1 Where the independent anteroom or the combined anteroom meets one of the following conditions, the stairwell may not be provided with a smoke protection system:
1) Fully open balcony or concave corridor is adopted;
2) There are two or more openable exterior windows with different orientations, the area of two exterior windows in the independent anteroom is not less than 2.0m2 respectively, and that of two exterior windows in the combined anteroom is not less than 3.0m2 respectively.
2 If the mechanically pressurized air supply outlet of the independent anteroom, shared anteroom and combined anteroom is arranged at the top of the anteroom or on the wall surface directly facing the entrance of the anteroom, the stairwell may be provided with a natural ventilation system; if not, the stairwell shall be provided with a mechanical pressurization system.
3 If the smoke-proof stairwell is provided with natural ventilation above the height of podium, mechanical pressurization system shall be adopted for the independent anteroom, shared anteroom and combined anteroom of the podium without natural ventilation condition, and the arrangement mode of the air supply outlet of independent anteroom, shared anteroom and combined anteroom shall meet the requirements of Item 2 in this subclause.
3.1.4 For the anterooms of smoke-proof stairwell and fire elevator in underground part of the building, mechanical pressurization system shall be adopted if the natural ventilation is not provided or is unqualified.
3.1.5 The arrangement of mechanical pressurization system in smoke-proof stairwell and its anteroom shall meet the following requirements:
1 General provisions
2 Terms and symbols
2.1 Terms
2.2 Symbols
3 Smoke protection system design
3.1 General requirements
3.2 Natural ventilation facilities
3.3 Mechanical pressurization facilities
3.4 Calculation of air volume in mechanical pressurization system
4 Smoke exhaust system design
4.1 General requirements
4.2 Smoke control zone
4.3 Natural smoke exhaust facilities
4.4 Mechanical smoke exhaust facilities
4.5 Air makeup system
4.6 Calculation of smoke exhaust system
5 System control
5.1 Smoke protection system
5.2 Smoke exhaust system
6 System construction
6.1 General requirements
6.2 Field inspection
6.3 Air duct installation
6.4 Duct accessory installation
6.5 Fan installation
7 System commissioning
7.1 General requirements
7.2 Single machine commissioning
7.3 Linked commissioning
8 System acceptance
8.1 General requirements
8.2 Project acceptance
9 Maintenance management
Annex A Mechanical exhaust smoke volume of different fire sizes
Annex B Maximum allowable smoke exhaust volume at the smoke exhaust inlet
Annex C Classification of subsection and subitem works in smoke protection and exhaust systems
Annex D Quality inspection records during construction
Annex E Inspection records for project quality control data of smoke protection and exhaust systems
Annex F Inspection records for smoke protection and exhaust project
Annex G Inspection items for maintenance management of smoke protection and exhaust systems
Explanation of wording in this standard
List of quoted standards
Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
According to the requirements of Document JIANBIAO [2006] No.77 issued by the Ministry of Housing and Urban-Rural Development of the People's Republic of China - Notice on printing and distributing the development and revision plan on engineering construction standards and codes in 2006 (first batch), this standard is formulated by the Sichuan Fire Research Institute of Ministry of Public Security jointly with Shanghai Public Security Fire Corps and other organizations concerned.
In the process of formulating this standard, the drafting group, following the relevant national laws, regulations and technical standards, thoroughly investigated the design and engineering application of the smoke protection and exhaust systems in buildings, carefully summarized the fire accident lessons and the engineering application practice of smoke protection and exhaust systems in buildings, referred to the domestic and foreign relevant standards and codes, adopted the advanced scientific research achievements, extensively solicited the opinions of design, supervision, construction, product manufacture, fire supervision and other relevant units, and finalized this standard through review.
The standard consists of 9 clauses and 7 annexes, with the main technical contents as follows: General provisions, Terms and symbols; Smoke protection system design, Smoke exhaust system design, System control, System construction, System commissioning, System acceptance, Maintenance management, etc.
The provisions printed in bold type in this standard are compulsory and must be enforced strictly.
The Ministry of Housing and Urban-Rural Development of the People's Republic of China is in charge of the administration of this standard and the explanation of the compulsory provisions, the Fire Department of Ministry of Public Security is in charge of routine management, and Sichuan Fire Research Institute of Ministry of Public Security is responsible for the explanation of specific technical contents. During the process of implementing this standard, all relevant organizations are kindly requested to sum up experience and accumulate information carefully in combination with engineering practice, and feed the relevant opinions and suggestions back to Sichuan Fire Research Institute of Ministry of Public Security (address: No.69, Jinke South Road, Jinniu District, Chengdu City, Sichuan Province, 610036, China) for future reference in revision.
Contents
1 General provisions 1
2 Terms and symbols 2
2.1 Terms 2
2.2 Symbols 4
3 Smoke protection system design 8
3.1 General requirements 8
3.2 Natural ventilation facilities 10
3.3 Mechanical pressurization facilities 10
3.4 Calculation of air volume in mechanical pressurization system 13
4 Smoke exhaust system design 18
4.1 General requirements 18
4.2 Smoke control zone 19
4.3 Natural smoke exhaust facilities 20
4.4 Mechanical smoke exhaust facilities 22
4.5 Air makeup system 26
4.6 Calculation of smoke exhaust system 27
5 System control 35
5.1 Smoke protection system 35
5.2 Smoke exhaust system 35
6 System construction 38
6.1 General requirements 38
6.2 Field inspection 39
6.3 Air duct installation 42
6.4 Duct accessory installation 45
6.5 Fan installation 47
7 System commissioning 49
7.1 General requirements 49
7.2 Single machine commissioning 49
7.3 Linked commissioning 52
8 System acceptance 54
8.1 General requirements 54
8.2 Project acceptance 54
9 Maintenance management 58
Annex A Mechanical exhaust smoke volume of different fire sizes 59
Annex B Maximum allowable smoke exhaust volume at the smoke exhaust inlet 61
Annex C Classification of subsection and subitem works in smoke protection and exhaust systems 64
Annex D Quality inspection records during construction 65
Annex E Inspection records for project quality control data of smoke protection and exhaust systems 69
Annex F Inspection records for smoke protection and exhaust project 70
Annex G Inspection items for maintenance management of smoke protection and exhaust systems 72
Explanation of wording in this standard 73
List of quoted standards 74
1 General provisions
1.0.1 This standard is formulated with a view to rationally designing the smoke protection and exhaust systems, guaranteeing the construction quality, regulating the acceptance and maintenance management, reducing fire hazard and protecting personal and property safety.
1.0.2 It is applicable to the design, construction, acceptance and maintenance management of smoke protection and exhaust systems in the constructed, extended and renovated industrial and civil buildings. For the industrial and civil buildings for special purposes or with special requirements, the special requirements, if any, specified in the professional standards, may be followed.
1.0.3 The design of smoke protection and exhaust systems in buildings shall be safe, reliable, technologically advanced and economically reasonable by taking effective technical measures in combination with factors such as the characteristics and the fire smoke development law of buildings.
1.0.4 The equipment of the smoke protection and exhaust systems in buildings shall be the products in conformity with relevant current standards of the nation and the relevant access systems.
1.0.5 In addition to this standard, the design, construction, acceptance and maintenance management of smoke protection and exhaust systems in buildings shall also meet the requirements of the current relevant standards of the nation.
2 Terms and symbols
2.1 Terms
2.1.1 smoke protection system
system used for preventing the fire smoke from accumulating in the spaces such as stairwell, anteroom, refuge floor (room) in the manner of natural ventilation or preventing the fire smoke from entering the spaces such as stairwell, anteroom, refuge floor (room) in the manner of mechanical pressurization, which is classified into natural ventilation system and mechanical pressurization system
2.1.2 smoke exhaust system
system used for exhausting the fire smoke from the room, walkway and other spaces to the outdoors in the manner of natural smoke exhaust or mechanical smoke exhaust, which is classified into natural smoke exhaust system and mechanical smoke exhaust system
2.1.3 mechanical pressurization without air shaft
a kind of air supply mode directly applying mechanical pressurization for stairwell with fan, without using any air shaft
2.1.4 natural smoke exhaust
a kind of smoke exhaust mode directly exhausting the smoke to the outdoors through the building openings by using the buoyancy of hot fire smoke flow and the external wind pressure
2.1.5 natural smoke vent
openable exterior window or opening with smoke exhaust function, which can be opened automatically, manually or in thermal release or other modes
2.1.6 smoke plume
mixed smoke flow formed by fire smoke entraining the surrounding air, which may be classified into axisymmetric plume, balcony spill plume, window plume, etc. according to the flow condition of flame and smoke
2.1.7 axisymmetric plume
plume that does not contact with the surrounding walls or obstacles and is not disturbed by air flow
2.1.8 balcony spill plume
plume which spills from the door (window) beam of the room on fire, flows along the balcony or horizontal projections outside the room on fire, and overflows upwards to the spill to the adjacent tall space along the edge of balcony or horizontal projections
2.1.9 window plume
plume which spills from the openings such as door and window of the room or compartment on ventilation-limited fire to the adjacent tall space
2.1.10 draft curtain
a kind of smoke obstruction facility which is made of non-combustible material and is installed vertically under the roof, beam or suspended ceiling to form a certain smoke storage space in case of fire
2.1.11 smoke reservoir
a space located at the top of the building space and consisting of draft curtain, beam or a partition wall to reserve the fire smoke, of which the height is the design depth of the smoke layer
2.1.12 clear height
the height from the lower edge of the smoke layer to the indoor floor
2.1.13 mass flow rate of plume
the mass of the plume flowing through a horizontal section at a certain height per unit time, expressed in kg/s
2.1.14 combination fire and smoke damper
damper which is installed in the duct of mechanical smoke exhaust system, is normally open, but is closed when the smoke temperature in exhaust duct reaches 280℃ in case of fire and is capable of meeting the smoke leakage amount and fire integrity requirements within a certain time to prevent the smoke and fire, and is generally composed of damper body, blade, actuator, temperature sensor and other components
2.1.15 smoke damper
damper which is installed at the end (smoke suction inlet) of each branch duct of the mechanical smoke exhaust system, is normally closed and meets the smoke leakage amount requirements, and can be manually and electrically opened and closed to exhaust smoke in case of fire and is generally composed of damper body, blade, actuator and other components
2.1.16 smoke exhaust inlet
the smoke inlet in the mechanical smoke exhaust system
2.1.17 fixed window for fire forcible entry
exterior window arranged in the place without mechanical smoke protection and exhaust systems, of which the sashes are fixed and normally closed, and are easy to manually disassembled in case of fire to exhaust the smoke and heat from the fire field
2.1.18 fusible daylighting band
a facility made of the material that melts at 120℃ to 150℃ and does not produce droplets, which is placed in the upper part of the building to exhaust the smoke and heat from the fire field
2.1.19 independent anteroom
an anteroom that is only connected to an escape stairway
2.1.20 shared anteroom
an anteroom that is shared by two scissor stairwells (in residential building)
2.1.21 combined anteroom
an anteroom that is a combination of the anteroom of smoke-proof stairwell and anteroom of fire elevator
2.2 Symbols
2.2.1 Calculating geometric parameters
A——the effective air leakage area of each evacuation door;
Ak——the sectional area of an opening door;
A0——the total area of all air intakes;
Am——the area of a door;
Af——the area of a single air supply valve;
Ag——the total area of evacuation doors in anterooms;
Al——the total area of evacuation doors in stairwells;
Av——the sectional area of natural smoke vent;
Aw——the window opening area;
B——the long side size of air duct;
b——the distance from the opening to the edge of the balcony;
dm——the distance from the handle to the latch of the door;
db——the depth of the smoke layer below the lowest point of the suction inlet of smoke exhaust system;
D——the diameter of the air duct;
H——the net height of the space;
H′——the net height of the building in smoke exhaust space for single-storey space and the storey height of the highest evacuation floor for multi-storey space;
Hl——the height from the fuel surface to the balcony;
Hw——the window opening height;
Hq——the minimum clear height;
ω——the opening width of the fire source area;
W——the diffusion width of the plume;
Wm——the width of a single-leaf door;
Z——the height from the fuel surface to the bottom of the smoke layer;
Zl——the limit height of flame;
Zb——the height from the lower edge of the balcony to the bottom of the smoke layer;
Zw——the height from the upper edge of the window opening to the bottom of the smoke layer.
2.2.2 Calculating air volume and speed
g——the gravitational acceleration;
Lhigh——the allowable air leakage per unit time of the air duct per unit area in the high-pressure system;
Lj——the mechanical pressurization air supply volume of stairwell;
Llow——the allowable air leakage per unit time of the air duct per unit area in the low-pressure system;
Lmid——the allowable air leakage per unit time of the air duct per unit area in the middle-pressure system;
Ls——the mechanical pressurization air supply volume of anteroom;
L1——the air supply volume required to reach the specified air speed when the door is opened;
L2——the total air leakage volume of other door slots under the specified air speed value when the door is opened;
L3——the total air leakage volume of the normally closed air supply valve that is not opened;
Mρ——the mass flow rate of plume;
v——the air speed in the cross section of door opening;
V——the smoke exhaust volume;
Vmax——the maximum allowable smoke exhaust volume at the smoke exhaust inlet.
2.2.3 Calculating pressure, heat quantity and time
Cp——the specific heat of air at constant pressure;
F′——the total thrust of door;
Fdc——the force required to overcome the door closer at the door handle;
M——the opening moment of door closer;
ρ0——the gas density at ambient temperature;
P——the maximum allowable pressure difference of the evacuation door;
Pair duct——the working pressure of duct system;
ΔP——the average pressure difference for calculating the air leakage volume;
Q——the heat release rate;
Qc——the convection section of heat release rate;
t——the fire growth duration;
T——the average absolute temperature of the smoke layer;
T0——the absolute temperature of the environment;
△T——the difference between the average temperature of the smoke layer and the ambient temperature.
2.2.4 Calculation coefficients
α——the fire growth coefficient;
αw——the correction coefficient of window plume;
γ——the position coefficient of smoke exhaust;
C0——the flow coefficient of air intake;
Cv——the flow coefficient of natural smoke vent;
K——the convective heat release factor in the smoke;
n——an index.
2.2.5 Other calculating symbols
N1——the number of floors on which the evacuation door is designed to be open;
N2——the number of air-leaking evacuation doors;
N3——the number of air-leaking valves.
3 Smoke protection system design
3.1 General requirements
3.1.1 The design of smoke protection system in building shall adopt natural ventilation system and mechanical pressurization system according to factors such as the height and use nature of the building.
3.1.2 For the public and industrial buildings with building height of more than 50m and the residential buildings with building height of more than 100m, the mechanical pressurization system shall be adopted for their smoke-proof stairwell, independent anteroom, shared anteroom, combined anteroom and fire elevator anteroom.
3.1.3 For the public and industrial buildings with building height of less than or equal to 50m and the residential buildings with building height of less than or equal to 100m, the natural ventilation system shall be adopted for their smoke-proof stairwell, independent anteroom, shared anteroom, combined anteroom (except for the combination of shared anteroom and fire elevator anteroom) and fire elevator anteroom; mechanical pressurization system shall be adopted when the natural ventilation system cannot be arranged. The selection of smoke protection system shall also meet the following requirements:
1 Where the independent anteroom or the combined anteroom meets one of the following conditions, the stairwell may not be provided with a smoke protection system:
1) Fully open balcony or concave corridor is adopted;
2) There are two or more openable exterior windows with different orientations, the area of two exterior windows in the independent anteroom is not less than 2.0m2 respectively, and that of two exterior windows in the combined anteroom is not less than 3.0m2 respectively.
2 If the mechanically pressurized air supply outlet of the independent anteroom, shared anteroom and combined anteroom is arranged at the top of the anteroom or on the wall surface directly facing the entrance of the anteroom, the stairwell may be provided with a natural ventilation system; if not, the stairwell shall be provided with a mechanical pressurization system.
3 If the smoke-proof stairwell is provided with natural ventilation above the height of podium, mechanical pressurization system shall be adopted for the independent anteroom, shared anteroom and combined anteroom of the podium without natural ventilation condition, and the arrangement mode of the air supply outlet of independent anteroom, shared anteroom and combined anteroom shall meet the requirements of Item 2 in this subclause.
3.1.4 For the anterooms of smoke-proof stairwell and fire elevator in underground part of the building, mechanical pressurization system shall be adopted if the natural ventilation is not provided or is unqualified.
3.1.5 The arrangement of mechanical pressurization system in smoke-proof stairwell and its anteroom shall meet the following requirements:
Contents of GB 51251-2017
1 General provisions
2 Terms and symbols
2.1 Terms
2.2 Symbols
3 Smoke protection system design
3.1 General requirements
3.2 Natural ventilation facilities
3.3 Mechanical pressurization facilities
3.4 Calculation of air volume in mechanical pressurization system
4 Smoke exhaust system design
4.1 General requirements
4.2 Smoke control zone
4.3 Natural smoke exhaust facilities
4.4 Mechanical smoke exhaust facilities
4.5 Air makeup system
4.6 Calculation of smoke exhaust system
5 System control
5.1 Smoke protection system
5.2 Smoke exhaust system
6 System construction
6.1 General requirements
6.2 Field inspection
6.3 Air duct installation
6.4 Duct accessory installation
6.5 Fan installation
7 System commissioning
7.1 General requirements
7.2 Single machine commissioning
7.3 Linked commissioning
8 System acceptance
8.1 General requirements
8.2 Project acceptance
9 Maintenance management
Annex A Mechanical exhaust smoke volume of different fire sizes
Annex B Maximum allowable smoke exhaust volume at the smoke exhaust inlet
Annex C Classification of subsection and subitem works in smoke protection and exhaust systems
Annex D Quality inspection records during construction
Annex E Inspection records for project quality control data of smoke protection and exhaust systems
Annex F Inspection records for smoke protection and exhaust project
Annex G Inspection items for maintenance management of smoke protection and exhaust systems
Explanation of wording in this standard
List of quoted standards
