【 Weak current College 】 on the fire code for tall buildings and the architectural design fire protection standard of advice (go)

With social progress, our building mechanical smoke problem is becoming more and more attention, the standard is also increasingly close to developed countries. States to the high-rise buildings fire code (hereinafter referred to as the "regulations") and the architectural design of the fire code (hereinafter buildings》) also has been to improve the provisions. The author in long-term engineering design practice that the doctrine of "(GB50045-95, 2001 Edition) and buildings》 (GBJ16-87 revision, April 2001, with local amendments) some provisions were not perfect, here come discuss with colleagues.

1 smoke staircase and vestibule of mechanical smoke
The explanation on the mechanical smoke section 8.3.1.2 stipulates: "the use of natural gas in the smoke of the staircase does not have natural smoke conditions before the Chamber, should be set independent mechanical pressurization for smoke control facilities".

The explanation on the smoke, 8.4.3 stipulates: "with podium of smoke control in high-rise buildings and its staircase room, fire the elevator room or shared front room, when the podium above use can be opened for natural smoke outside Windows, podium section does not have smoke condition, its front room or shared room should be set before the partial positive pressure ventilation system, positive pressure value should be consistent with the provisions in article 8.3.7", while the provisions of article 8.3.7 is: "mechanical pressurization of pressure, in addition to the calculation of the most negative loop pipe head loss, there is more pressure should be, the remaining pressure value should meet the following requirements: 8.3.7.1 smoke staircase to 50Pa 40Pa ~; 8.3.7.2 before the former rooms, shared rooms, fire the elevator room, closed asylum layer (room)-5Pa ~ 30Pa".

(1) the actual engineering design often happen: smoke staircase with natural smoke conditions (i.e. staircase to open window size greater than 2.0m2), and smoke stairs room does not have natural smoke conditions, pursuant to the provisions of the regulations of section 8.3.1.2 stairs of the smoke can not set the positive pressure ventilation systems, natural gas, and its former room set positive pressure ventilation system, front room on each floor has a normally closed leafy áir, fire protection control center control open and close. When building a fire, the fire control centre control open fires layer and its phase before the Office of the pro level pressure supply outlet forward room air (usually this control), smoke stairway can open window then take automatic or manual opening for natural gas. At the same time, the asylum personnel to constantly move forward, and smoke evacuation staircases, then the high pressure air before, not only will flow to the corridor and staircase will flow to the smoke. Therefore, the front room of positive pressure ventilation system fan if you press the explanation on the table are calculated 8.3.2-4, front room and smoke staircase of positive pressure value is not possible to guarantee compliance with the regulations of law article 8.3.7 of the request, or even occur on fire floor corridor of flue gas pressure in the heat, pressure, force, floating pressure under the combined action of entering the room.

(2) also in practical engineering also exist in accordance with the provisions of the regulations of section 8.4.3, namely the Ministry of the annex of these rooms can be opened in front of Windows, use of natural smoke exhaust manner; podium portion of the front room does not have natural smoke conditions, setting local positive pressure ventilation system; with its adjacent smoke staircase with natural smoke conditions, use of natural gas. When building podium above there is a fire, smoke, fire stairs and former room exterior Windows take automatic or manual opening for natural gas. Same as mentioned above, the asylum personnel to constantly move forward, and smoke evacuation staircases, than the above situation worse, the front room and smoke layer staircase and ignition is in the negative pressure than the corridor area State, therefore, the corridor in front of the flue gas is bound into the Chamber and smoke staircase, is not conducive to evacuate.

Stairs are an important channel for evacuation, smoke stairway is not allowed to smoke. In the case of domestic and foreign many fire found that the body temperature of combustion will produce a highly toxic or flammable gases sizeable, throw an instant deflagration, evacuation and rescue difficulties that intoxication, asphyxia, injuries caused great damage. Therefore, building fires must guarantee the unimpeded evacuation channels that guarantee smoke staircase and vestibule, combined with front room and fire the elevator room is a smoke-free status. In my view, whether or not smoke in front of the stairs and combined front room, room, and fire the elevator room availability of natural smoke conditions, should adopt the way of natural smoke extraction, and use of mechanical means that the settings in the smoke of positive pressure ventilation system. Recommends that the doctrine of "mechanical smoke part of improving design standards, cancel the natural way, so that the smoke exhaust system stairways really played the role of the smoke. Positive pressure ventilation system settings and pressurized air, in accordance with the doctrine of "table 8.3.2-1, table 2, table 8.3.2-8.3.2-3.

2 Natural smoke within the aisle
The explanation on the natural smoke exhaust section 8.2.2.3 requirements: the maximum length, in the aisle 60m can open Windows within an area of not less than 2% of the sidewalk area, you can use natural gas.

In the implementation of the regulations on the provision, due to the differences in the norms, but also designers and fire protection approval Department disagree. For example: in a class of high-rise building design in the aisle length 54m, one side of the aisle have to open the window, and you can open the window area is greater than the sidewalk area within 2%. Designer natural smoke, according to the regulations of law No. 8.2.2.3 terms is compliant. However, in the fire protection design approval, the Fire Department should be set within the aisle by mechanical exhaust system on the grounds that, in the aisle only external window can be opened, within the aisle length does not allow more than 30m. Due to the resistance of the provisions of article 8.2.2.3 inadequate, expressed without the provision of instructions and explanations, resulting in the implementation of the provisions of the inconvenience. In my view, if it finds that the Fire Department of the above explanation is correct, then the doctrine of the terms of article 8.2.2.3 should read: "the length does not exceed the internal walkways, 60m each side can be opened window area and should not be less than the sidewalk surfaceProduct of 2%. ”

3 buildings》 mechanical smoke extraction
(1) in April 2000, the Ministry of construction on the engineering construction standard partial amendment proclamation (No. 27) on buildings》 had partial revision. In partial revision clause provided for in articles 5.1.1a: "ring, dance halls, nightclubs, shows, karaoke (including with karaoke function restaurant), game Hall (with electronic entertainment Hall), sauna (in addition to bath section), Internet Cafe, dance installstion, should be set in a building fire-resistant Grade II, the first floor, second-tier or three-tier depends on external sites should not be set in a bag-shaped both sides of the aisle and end. When you have to set the other floors in the building, there should satisfy the following requirements:

A. should not be set on the second floor and ground floor on the second floor of the following, when set in the ground floor, the basement floor and outdoor entrance floor-height difference should not be greater than 10m;

B. a Hall, room area should not be greater than 200m2;

C. should set smoke, smoke extraction facilities. For underground rooms, there is no window in the room or fixed sash of ground rooms, as well as more than 20m and no natural smoke evacuation of the aisle, or directly on the natural ventilation but longer than 40m evacuation in the aisle, mechanical smoke extraction facilities should be set.

The above mentioned should be set in the only mechanical smoke extraction facilities, but not the amount should be how to smoke or as existing national provisions to which standard. The provisions of article 5.1.1a jiangui is "building" the contents of the chapter, the author believes buildings》 IX "heating, ventilating and air conditioning" should also be increased with respect to the terms of the mechanical smoke.

(2) buildings》 General provisions description in 1.0.3: such as IRC, Town Hall, etc more than 24-storey public buildings included in the scope of this specification.

Modern sports construction electrical equipment, line complex, ventilation and air conditioning pipe extending in all directions, are caused by the spread of fire. Whether it is a multifunctional Sports Centre, swimming pool, Indoor skating rink or ice hockey rink, in the event of fire, in the competition Hall of flame Center, with vertical upward flow 4 ~ 6m/s spread to the ceiling and roof truss, now the Museum's various shaft, such as the fresh air and exhaust air, air, air and water wells, staircase and the elevator shaft and so have become the big chimney of channeling the fire, because of the chimney effect caused by the rapid expansion of pyrotechnic effects, even through the rapid dissemination of expansion joints. When the fire burning 6min, flame temperature will rise to 900 ° c above, since the fire burning and baking, etc, so that the steel roof strength reduction, the large spaces around the fire in General 15min steel roof will collapse. In this Hall smoke, fire and flames, MI vines audience will filled with confusion, causing significant casualties and severe economic losses. Therefore sports building set fire smoke exhaust is very necessary. The author recommends buildings》 should increase the smoke of the "mechanical" provisions.