标准编号:	GB 51251-2017
中文名称:	建筑防烟排烟系统技术标准
英文名称:	Technical standard for smoke management systems in buildings
行业分类:	GB    国家标准
发布机构:	中华人民共和国住房和城乡建设部
发布日期:	2017-11-20
实施日期:	2018-8-1
标准状态:	现行
翻译语言:	英文
文件格式:	PDF
中文字符数:	60000 字
翻译价格(元):	3800.00 元
交付时间:	付款后 1 个工作日

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

1 总 则
1.0.1 为了合理设计建筑防烟、排烟系统。保证施工质量，规范验收和维护管理，减少火灾危害，保护人身和财产安全，制定本标准。
1.0.2 本标准适用于新建、扩建和改建的工业与民用建筑的防烟、排烟系统的设计、施工、验收及维护管理。对于有特殊用途或特殊要求的工业与民用建筑，当专业标准有特别规定的，可从其规定。
1.0.3 建筑防烟、排烟系统的设计，应结合建筑的特性和火灾烟气的发展规律等因素，采取有效的技术措施，做到安全可靠、技术先进、经济合理。
1.0.4建筑防烟、排烟系统的设备，应选用符合国家现行有关标准和有关准入制度的产品。
1.0.5建筑防烟、排烟系统的设计、施工、验收及维护管理除执行本标准外，尚应符合国家现行有关标准的要求。
2术语和符号
2.1 术 语
2.1.1 防烟系统 smoke protection system
通过采用自然通风方式，防止火灾烟气在楼梯间、前室、避难层(间)等空间内积聚，或通过采用机械加压送风方式阻止火灾烟气侵入楼梯间、前室、避难层(间)等空间的系统，防烟系统分为自然通风系统和机械加压送风系统。
2.1.2排烟系统 smoke exhaust system
采用自然排烟或机械排烟的方式，将房间、走道等空间的火灾烟气排至建筑物外的系统，分为自然排烟系统和机械排烟系统。
2.1.3直灌式机械加压送风 mechanical pressurization without air shaft
无送风井道，采用风机直接对楼梯间进行机械加压的送风方式。
2.1.4 自然排烟 natural smoke exhaust
利用火灾热烟气流的浮力和外部风压作用，通过建筑开口将建筑内的烟气直接排至室外的排烟方式。
2.1.5 自然排烟窗(口) natural smoke vent
具有排烟作用的可开启外窗或开口，可通过自动、手动、温控释放等方式开启。
2.1.6 烟羽流 smoke plume
火灾时烟气卷吸周围空气所形成的混合烟气流。烟羽流按火焰及烟的流动情形，可分为轴对称型烟羽流、阳台溢出型烟羽流、窗口型烟羽流等。
2.1.7轴对称型烟羽流 axisymmetric plume
上升过程不与四周墙壁或障碍物接触，并且不受气流干扰的烟羽流。
2.1.8 阳台溢出型烟羽流 balcony spill plume
从着火房间的门(窗)梁处溢出，并沿着火房间外的阳台或水平突出物流动，至阳台或水平突出物的边缘向上溢出至相邻高大空间的烟羽流。
2.1.9 窗口型烟羽流 window plume
从发生通风受限火灾的房间或隔间的门、窗等开口处溢出至相邻高大空间的烟羽流。
2.1.10挡烟垂壁draft curtain
用不燃材料制成，垂直安装在建筑顶棚、梁或吊顶下，能在火灾时形成一定的蓄烟空间的挡烟分隔设施。
2.1.11 储烟仓 smoke reservoir
位于建筑空间顶部，由挡烟垂壁、梁或隔墙等形成的用于蓄积火灾烟气的空间。储烟仓高度即设计烟层厚度。
2.1.12清晰高度 clear height
烟层下缘至室内地面的高度。
2.1.13烟羽流质量流量 mass flow rate of plume
单位时间内烟羽流通过某一高度的水平断面的质量。单位为kg/s。
2.1.14排烟防火阀 combination fire and smoke damper
安装在机械排烟系统的管道上，平时呈开启状态，火灾时当排烟管道内烟气温度达到280℃时关闭，并在一定时间内能满足漏烟量和耐火完整性要求，起隔烟阻火作用的阀门。一般由阀体、叶片、执行机构和温感器等部件组成。
2.1.15排烟阀 smoke damper
安装在机械排烟系统各支管端部(烟气吸入口)处，平时呈关闭状态并满足漏风量要求，火灾时可手动和电动启闭，起排烟作用的阀门。一般由阀体、叶片、执行机构等部件组成。
2.1.16排烟口 smoke exhaust inlet
机械排烟系统中烟气的入口。
2.1.17 固定窗 fixed window for fire forcible entry
设置在没有机械防烟排烟系统的场所中，窗扇固定、平时不可开启，仅在火灾时便于人工破拆以排出火场中的烟和热的外窗。
2.1.18 可熔性采光带(窗) fusible daylighting band
采用在120℃～l50℃能自行熔化且不产生熔滴的材料制作，设置在建筑空间上部，用于排出火场中的烟和热的设施。
2.1.19 独立前室 independent anteroom
只与一部疏散楼梯相连的前室。
2.1.20共用前室 shared anteroom
(居住建筑)剪刀楼梯间的两个楼梯间共用同一前室时的前室。
2.1.21 合用前室 combined anteroom
防烟楼梯间前室与消防电梯前室合用时的前室。
2.2 符 号
2.2.1计算几何参数
A——每个疏散门的有效漏风面积；
Ak——开启门的截面面积；
A0——所有进气口总面积；
Am——门的面积；
Af——单个送风阀门的面积；
Ag——前室疏散门的总面积；
Al——楼梯间疏散门的总面积；
Av——自然排烟窗(口)截面积；
Aw——窗口开口面积；
B——风管长边尺寸；
b——从开口至阳台边沿的距离；
dm——门的把手到门闩的距离；
db——排烟系统吸入口最低点之下烟气层厚度；
D——风管直径；
H——空间净高；
H′——对于单层空间，取排烟空间的建筑净高度；对于多层空间，取最高疏散楼层的层高；
Hl——燃料面至阳台的高度；
Hw——窗口开口的高度；
Hq——最小清晰高度；
w——火源区域的开口宽度；
W——烟羽流扩散宽度；
Wm——单扇门的宽度；
Z——燃料面到烟层底部的高度；
Z1——火焰极限高度；
Zb——从阳台下缘至烟层底部的高度；
Zw——窗口开口的上缘到烟层底部的高度。
2.2.2计算风量、风速
g——重力加速度；
Lbigh——高压系统单位面积风管单位时间内的允许漏风量；
Lj——楼梯间的机械加压送风量；
Llow——低压系统单位面积风管单位时间内的允许漏风量；
Lmid——中压系统单位面积风管单位时间内的允许漏风量；
Ls——前室的机械加压送风量；
L1——门开启时，达到规定风速值所需的送风量；
L2——门开启时，规定风速值下的其他门缝漏风总量；
L3——未开启的常闭送风阀的漏风总量；
Mp——烟羽流质量流量；
v——门洞断面风速；
V——排烟量；
Vmax——排烟口最大允许排烟量。
2.2.3计算压力、热量、时间
Cp——空气的定压比热；
F′——门的总推力；
Fdc——门把手处克服闭门器所需的力；
M——闭门器的开启力矩；
ρ0——环境温度下的气体密度；
P——疏散门的最大允许压力差；
P风管——风管系统工作压力；
ΔP——计算漏风量的平均压力差；
Q——热释放速率；
Qc——热释放速率中的对流部分；
t——火灾增长时间；
T——烟层的平均绝对温度；
T0——环境的绝对温度；
△T——烟层平均温度与环境温度之差。
2.2.4计算系数
α——火灾增长系数；
αw——窗口型烟羽流的修正系数；
γ——排烟位置系数；
C0——进气口流量系数；
Cv——自然排烟窗(口)流量系数；
K——烟气中对流放热量因子；
n——指数。
2.2.5计算其他符号
N1——设计疏散门开启的楼层数量；
N2——漏风疏散门的数量；
N3——漏风阀门的数量。
3防烟系统设计
3.1 一般规定
3.1.1 建筑防烟系统的设计应根据建筑高度、使用性质等因素，采用自然通风系统或机械加压送风系统。
3.1.2 建筑高度大于50m的公共建筑、工业建筑和建筑高度大于100m的住宅建筑，其防烟楼梯间、独立前室、共用前室、合用前室及消防电梯前室应采用机械加压送风系统。
3.1.3 建筑高度小于或等于50m的公共建筑、工业建筑和建筑高度小于或等于100m的住宅建筑，其防烟楼梯间、独立前室、共用前室、合用前室(除共用前室与消防电梯前室合用外)及消防电梯前室应采用自然通风系统；当不能设置自然通风系统时，应采用机械加压送风系统。防烟系统的选择，尚应符合下列规定：
1 当独立前室或合用前室满足下列条件之一时，楼梯间可不设置防烟系统：
1)采用全敞开的阳台或凹廊；
2)设有两个及以上不同朝向的可开启外窗，且独立前室两个外窗面积分别不小于2.0m2，合用前室两个外窗面积分别不小于3.0m2。
2 当独立前室、共用前室及合用前室的机械加压送风口设置在前室的顶部或正对前室入口的墙面时，楼梯间可采用自然通风系统；当机械加压送风口未设置在前室的顶部或正对前室入口的墙面时，楼梯间应采用机械加压送风系统。
3 当防烟楼梯间在裙房高度以上部分采用自然通风时，不具备自然通风条件的裙房的独立前室、共用前室及合用前室应采用机械加压送风系统，且独立前室、共用前室及合用前室送风口的设置方式应符合本条第2款的规定。
3.1.4建筑地下部分的防烟楼梯间前室及消防电梯前室，当无自然通风条件或自然通风不符合要求时。应采用机械加压送风系统。
3.1.5 防烟楼梯间及其前室的机械加压送风系统的设置应符合下列规定：
1 建筑高度小于或等于50m的公共建筑、工业建筑和建筑高度小于或等于100m的住宅建筑，当采用独立前室且其仅有一个门与走道或房间相通时，可仅在楼梯间设置机械加压送风系统；当独立前室有多个门时，楼梯间、独立前室应分别独立设置机械加压送风系统。
2 当采用合用前室时，楼梯间、合用前室应分别独立设置机械加压送风系统。
3 当采用剪刀楼梯时，其两个楼梯间及其前室的机械加压送风系统应分别独立设置。
3.1.6封闭楼梯间应采用自然通风系统，不能满足自然通风条件的封闭楼梯间，应设置机械加压送风系统。当地下、半地下建筑(室)的封闭楼梯间不与地上楼梯间共用且地下仅为一层时，可不设置机械加压送风系统，但首层应设置有效面积不小于1.2m2的可开启外窗或直通室外的疏散门。
3.1.7 设置机械加压送风系统的场所，楼梯间应设置常开风口，前室应设置常闭风口；火灾时其联动开启方式应符合本标准第5.1.3条的规定。
3.1.8避难层的防烟系统可根据建筑构造、设备布置等因素选择自然通风系统或机械加压送风系统。
3.1.9 避难走道应在其前室及避难走道分别设置机械加压送风系统，但下列情况可仅在前室设置机械加压送风系统：
1 避难走道一端设置安全出口，且总长度小于30m；
2 避难走道两端设置安全出口，且总长度小于60m。
3.2 自然通风设施
3.2.1 采用自然通风方式的封闭楼梯间、防烟楼梯间，应在最高部位设置面积不小于1.0m2的可开启外窗或开口：当建筑高度大于10m时，尚应在楼梯间的外墙上每5层内设置总面积不小于2.0m2的可开启外窗或开口，且布置间隔不大于3层。
3.2.2 前室采用自然通风方式时，独立前室、消防电梯前室可开启外窗或开口的面积不应小于2.0m2，共用前室、合用前室不应小于3.0m2。
3.2.3 采用自然通风方式的避难层(间)应设有不同朝向的可开启外窗，其有效面积不应小于该避难层(间)地面面积的2％，且每个朝向的面积不应小于2.0m2。
3.2.4可开启外窗应方便直接开启，设置在高处不便于直接开启的可开启外窗应在距地面高度为1.3m～1.5m的位置设置手动开启装置。
3.3机械加压送风设施
3.3.1建筑高度大于100m的建筑，其机械加压送风系统应竖向分段独立设置，且每段高度不应超过100m。
3.3.2 除本标准另有规定外，采用机械加压送风系统的防烟楼梯间及其前室应分别设置送风井(管)道，送风口(阀)和送风机。
3.3.3 建筑高度小于或等于50m的建筑，当楼梯间设置加压送风井(管)道确有困难时，楼梯间可采用直灌式加压送风系统，并应符合下列规定：
1 建筑高度大于32m的高层建筑，应采用楼梯间两点部位送风的方式，送风口之间距离不宜小于建筑高度的1/2；
2送风量应按计算值或本标准第3.4.2条规定的送风量增加20％；
3加压送风口不宜设在影响人员疏散的部位。
3.3.4设置机械加压送风系统的楼梯间的地上部分与地下部分，其机械加压送风系统应分别独立设置。当受建筑条件限制，且地下部分为汽车库或设备用房时，可共用机械加压送风系统，并应符合下列规定：
1 应按本标准第3.4.5条的规定分别计算地上、地下部分的加压送风量，相加后作为共用加压送风系统风量；
2 应采取有效措施分别满足地上、地下部分的送风量的要求。
3.3.5 机械加压送风风机宜采用轴流风机或中、低压离心风机，其设置应符合下列规定：
1送风机的进风口应直通室外，且应采取防止烟气被吸入的措施。
2送风机的进风口宜设在机械加压送风系统的下部。
3送风机的进风口不应与排烟风机的出风口设在同一面上。当确有困难时，送风机的进风口与排烟风机的出风口应分开布置，且竖向布置时，送风机的进风口应设置在排烟出口的下方，其两者边缘最小垂直距离不应小于6.0m；水平布置时，两者边缘最小水平距离不应小于20.0m。
4送风机宜设置在系统的下部，且应采取保证各层送风量均匀性的措施。
5 送风机应设置在专用机房内，送风机房并应符合现行国家标准《建筑设计防火规范》GB 50016的规定。
6 当送风机出风管或进风管上安装单向风阀或电动风阀时，应采取火灾时自动开启阀门的措施。
3.3.6 加压送风口的设置应符合下列规定：
1 除直灌式加压送风方式外，楼梯间宜每隔2层～3层设一个常开式百叶送风口；
2前室应每层设一个常闭式加压送风口，并应设手动开启装置：
3送风口的风速不宜大于7m/s；
4送风口不宜设置在被门挡住的部位。
3.3.7 机械加压送风系统应采用管道送风，且不应采用土建风道。送风管道应采用不燃材料制作且内壁应光滑。当送风管道内壁为金属时，设计风速不应大于20m/s；当送风管道内壁为非金属时，设计风速不应大于15m/s；送风管道的厚度应符合现行国家标准《通风与空调工程施工质量验收规范》GB 50243的规定。
3.3.8机械加压送风管道的设置和耐火极限应符合下列规定：
1 竖向设置的送风管道应独立设置在管道井内，当确有困难时，未设置在管道井内或与其他管道合用管道井的送风管道，其耐火极限不应低于1.00h；
2水平设置的送风管道，当设置在吊顶内时，其耐火极限不应低于0.50h；当未设置在吊顶内时，其耐火极限不应低于1.00h。
3.3.9 机械加压送风系统的管道井应采用耐火极限不低于1.00h的隔墙与相邻部位分隔，当墙上必须设置检修门时应采用乙级防火门。
3.3.10 采用机械加压送风的场所不应设置百叶窗，且不宜设置可开启外窗。
3.3.11 设置机械加压送风系统的封闭楼梯间、防烟楼梯间，尚应在其顶部设置不小于1m2的固定窗。靠外墙的防烟楼梯间，尚应在其外墙上每5层内设置总面积不小于2m2的固定窗。
3.3.12设置机械加压送风系统的避难层(间)，尚应在外墙设置可开启外窗，其有效面积不应小于该避难层(间)地面面积的1％。有效面积的计算应符合本标准第4.3.5条的规定。
3.4机械加压送风系统风量计算
3.4.1 机械加压送风系统的设计风量不应小于计算风量的1.2倍。
3.4.2 防烟楼梯间、独立前室、共用前室、合用前室和消防电梯前室的机械加压送风的计算风量应由本标准第3.4.5条～第3.4.8条的规定计算确定。当系统负担建筑高度大于24m时，防烟楼梯间、独立前室、合用前室和消防电梯前室应按计算值与表3.4.2-1～表3.4.2-4的值中的较大值确定。
表3.4.2-1 消防电梯前室加压送风的计算风量
系统负担高度h(m) 加压送风量(m3/h)
246.0 2000 60m；具有自然对流条件时，不应大于75m

注：1 公共建筑、工业建筑中的走道宽度不大于2.5m时，其防烟分区的长边长度不应大于60m。
2 当空间净高大于9m时，防烟分区之间可不设置挡烟设施。
3汽车库防烟分区的划分及其排烟量应符合现行国家规范《汽车库、修车库、停车场设计防火规范》GB 50067的相关规定。
4.3自然排烟设施
4.3.1 采用自然排烟系统的场所应设置自然排烟窗(口)。
4.3.2 防烟分区内自然排烟窗(口)的面积、数量、位置应按本标准第4.6.3条规定经计算确定，且防烟分区内任一点与最近的自然排烟窗(口)之间的水平距离不应大于30m。当工业建筑采用自然排烟方式时，其水平距离尚不应大于建筑内空间净高的2.8倍；当公共建筑空间净高大于或等于6m，且具有自然对流条件时，其水平距离不应大于37.5m。
4.3.3 自然排烟窗(口)应设置在排烟区域的顶部或外墙，并应符合下列规定：
1 当设置在外墙上时，自然排烟窗(口)应在储烟仓以内，但走道、室内空间净高不大于3m的区域的自然排烟窗(口)可设置在室内净高度的1/2以上；
2 自然排烟窗(口)的开启形式应有利于火灾烟气的排出；
3 当房间面积不大于200m2时，自然排烟窗(口)的开启方向可不限；
4 自然排烟窗(口)宜分散均匀布置，且每组的长度不宜大于3.0m；
5设置在防火墙两侧的自然排烟窗(口)之间最近边缘的水平距离不应小于2.0m。
4.3.4厂房、仓库的自然排烟窗(口)设置尚应符合下列规定：
1 当设置在外墙时，自然排烟窗(口)应沿建筑物的两条对边均匀设置；
2 当设置在屋顶时，自然排烟窗(口)应在屋面均匀设置且宜采用自动控制方式开启；当屋面斜度小于或等于12°时，每200m2的建筑面积应设置相应的自然排烟窗(口)；当屋面斜度大于12°时，每400m2的建筑面积应设置相应的自然排烟窗(口)。
4.3.5 除本标准另有规定外，自然排烟窗(口)开启的有效面积尚应符合下列规定：
1 当采用开窗角大于70°的悬窗时，其面积应按窗的面积计算；当开窗角小于或等于70°时，其面积应按窗最大开启时的水平投影面积计算。
2 当采用开窗角大于70°的平开窗时，其面积应按窗的面积计算；当开窗角小于或等于70°时，其面积应按窗最大开启时的竖向投影面积计算。
3 当采用推拉窗时，其面积应按开启的最大窗口面积计算。
4 当采用百叶窗时，其面积应按窗的有效开口面积计算。
5 当平推窗设置在顶部时，其面积可按窗的1/2周长与平推距离乘积计算，且不应大于窗面积。
6 当平推窗设置在外墙时，其面积可按窗的1/4周长与平推距离乘积计算，且不应大于窗面积。
4.3.6 自然排烟窗(口)应设置手动开启装置，设置在高位不便于直接开启的自然排烟窗(口)，应设置距地面高度1.3m～1.5m的手动开启装置。净空高度大于9m的中庭、建筑面积大于2000m2的营业厅、展览厅、多功能厅等场所，尚应设置集中手动开启装置和自动开启设施。
4.3.7 除洁净厂房外，设置自然排烟系统的任一层建筑面积大于2500m2的制鞋、制衣、玩具、塑料、木器加工储存等丙类工业建筑。除自然排烟所需排烟窗(口)外，尚宜在屋面上增设可熔性采光带(窗)，其面积应符合下列规定：
1 未设置自动喷水灭火系统的，或采用钢结构屋顶，或采用预应力钢筋混凝土屋面板的建筑，不应小于楼地面面积的10％；
2其他建筑不应小于楼地面面积的5％。
注：可熔性采光带(窗)的有效面积应按其实际面积计算。
4.4机械排烟设施
4.4.1 当建筑的机械排烟系统沿水平方向布置时，每个防火分区的机械排烟系统应独立设置。
4.4.2 建筑高度超过50m的公共建筑和建筑高度超过100m的住宅，其排烟系统应竖向分段独立设置，且公共建筑每段高度不应超过50m，住宅建筑每段高度不应超过100m。
4.4.3 排烟系统与通风、空气调节系统应分开设置；当确有困难时可以合用，但应符合排烟系统的要求，且当排烟口打开时，每个排烟合用系统的管道上需联动关闭的通风和空气调节系统的控制阀门不应超过10个。
4.4.4 排烟风机宜设置在排烟系统的最高处，烟气出口宜朝上，并应高于加压送风机和补风机的进风口，两者垂直距离或水平距离应符合本标准第3.3.5条第3款的规定。
4.4.5排烟风机应设置在专用机房内，并应符合本标准第3.3.5条第5款的规定，且风机两侧应有600mm以上的空间。对于排烟系统与通风空气调节系统共用的系统，其排烟风机与排风风机的合用机房应符合下列规定：
1 机房内应设置自动喷水灭火系统；
2 机房内不得设置用于机械加压送风的风机与管道；
3 排烟风机与排烟管道的连接部件应能在280℃时连续30min保证其结构完整性。
4.4.6排烟风机应满足280℃时连续工作30min的要求，排烟风机应与风机入口处的排烟防火阀连锁，当该阀关闭时，排烟风机应能停止运转。
4.4.7机械排烟系统应采用管道排烟，且不应采用土建风道。排烟管道应采用不燃材料制作且内壁应光滑。当排烟管道内壁为金属时。管道设计风速不应大于20m/s；当排烟管道内壁为非金属时，管道设计风速不应大于15m/s；排烟管道的厚度应按现行国家标准《通风与空调工程施工质量验收规范》GB 50243的有关规定执行。
4.4.8 排烟管道的设置和耐火极限应符合下列规定：
1 排烟管道及其连接部件应能在280℃时连续30min保证其结构完整性。
2竖向设置的排烟管道应设置在独立的管道井内，排烟管道的耐火极限不应低于0.50h。
3水平设置的排烟管道应设置在吊顶内，其耐火极限不应低于0.50h；当确有困难时，可直接设置在室内，但管道的耐火极限不应小于1.00h。
4设置在走道部位吊顶内的排烟管道，以及穿越防火分区的排烟管道，其管道的耐火极限不应小于1.00h，但设备用房和汽车库的排烟管道耐火极限可不低于0.50h。
4.4.9 当吊顶内有可燃物时，吊顶内的排烟管道应采用不燃材料进行隔热，并应与可燃物保持不小于150mm的距离。
4.4.10排烟管道下列部位应设置排烟防火阀：
1 垂直风管与每层水平风管交接处的水平管段上；
2 一个排烟系统负担多个防烟分区的排烟支管上；
3排烟风机入口处：
4穿越防火分区处。
4.4.11 设置排烟管道的管道井应采用耐火极限不小于1.00h的隔墙与相邻区域分隔；当墙上必须设置检修门时，应采用乙级防火门。
4.4.12 排烟口的设置应按本标准第4.6.3条经计算确定。且防烟分区内任一点与最近的排烟口之间的水平距离不应大于30m。除本标准第4.4.13条规定的情况以外.排烟口的设置尚应符合下列规定：
1 排烟口宜设置在顶棚或靠近顶棚的墙面上。
2排烟口应设在储烟仓内，但走道、室内空间净高不大于3m的区域，其排烟口可设置在其净空高度的1/2以上；当设置在侧墙时，吊顶与其最近边缘的距离不应大于0.5m。
3对于需要设置机械排烟系统的房间，当其建筑面积小于50m2时，可通过走道排烟，排烟口可设置在疏散走道；排烟量应按本标准第4.6.3条第3款计算。
4火灾时由火灾自动报警系统联动开启排烟区域的排烟阀或排烟口，应在现场设置手动开启装置。
5 排烟口的设置宜使烟流方向与人员疏散方向相反，排烟口与附近安全出口相邻边缘之间的水平距离不应小于1.5m。
6 每个排烟口的排烟量不应大于最大允许排烟量，最大允许排烟量应按本标准第4.6.14条的规定计算确定。
7排烟口的风速不宜大于10m/s。
4.4.13 当排烟口设在吊顶内且通过吊顶上部空间进行排烟时，应符合下列规定：
1 吊顶应采用不燃材料，且吊顶内不应有可燃物；
2封闭式吊顶上设置的烟气流入口的颈部烟气速度不宜大于1.5m/s；
3非封闭式吊顶的开孔率不应小于吊顶净面积的25％，且孔洞应均匀布置。
4.4.14按本标准第4.1.4条规定需要设置固定窗时，固定窗的布置应符合下列规定：
1 非顶层区域的固定窗应布置在每层的外墙上；
2顶层区域的固定窗应布置在屋顶或顶层的外墙上，但未设置自动喷水灭火系统的以及采用钢结构屋顶或预应力钢筋混凝土屋面板的建筑应布置在屋顶。
4.4.15 固定窗的设置和有效面积应符合下列规定：
1 设置在顶层区域的固定窗，其总面积不应小于楼地面面积的2％。
2设置在靠外墙且不位于顶层区域的固定窗，单个固定窗的面积不应小于1m2，且间距不宜大于20m，其下沿距室内地面的高度不宜小于层高的1/2。供消防救援人员进入的窗口面积不计入固定窗面积，但可组合布置。
3设置在中庭区域的固定窗，其总面积不应小于中庭楼地面面积的5％。
4 固定玻璃窗应按可破拆的玻璃面积计算，带有温控功能的可开启设施应按开启时的水平投影面积计算。
4.4.16 固定窗宜按每个防烟分区在屋顶或建筑外墙上均匀布置且不应跨越防火分区。
4.4.17 除洁净厂房外，设置机械排烟系统的任一层建筑面积大于2000m2的制鞋、制衣、玩具、塑料、木器加工储存等丙类工业建筑，可采用可熔性采光带(窗)替代固定窗，其面积应符合下列规定：
1 未设置自动喷水灭火系统的或采用钢结构屋顶或预应力钢筋混凝土屋面板的建筑，不应小于楼地面面积的10％；
2 其他建筑不应小于楼地面面积的5％；
注：可熔性采光带(窗)的有效面积应按其实际面积计算。